2007 Vol. 15, No. S2
2007, 15(S2): 1-6.
Abstract Based on the experience gained by the author in 50 years of engineering geological activities and the present situation of engineering geological work in the country,this paper is attempting to explore the core value of engineering geology. As originated from geosciences,engineering geology has its depth of knowledge of geology. However,the integration of geological and engineering sciences enables the engineering geology to have the capability of interpretation of geological structure and phenomenon on its engineering meanings,and to create the identifi-canon of engineering geology as a branch of modern sciences. Through the engineering geological observation,judg-ment,evaluation,prediction and decision making,the core value of engineering geology can be realized. In the en-gineering geological work the theory and methodology of geology and the identification of engineering geology should be implemented and be promoted,but the advanced theoretical and technology of relevant sciences should be ap-plied to achieve new advancement of engineering geology in serving the reconstruction of the country.
Abstract Based on the experience gained by the author in 50 years of engineering geological activities and the present situation of engineering geological work in the country,this paper is attempting to explore the core value of engineering geology. As originated from geosciences,engineering geology has its depth of knowledge of geology. However,the integration of geological and engineering sciences enables the engineering geology to have the capability of interpretation of geological structure and phenomenon on its engineering meanings,and to create the identifi-canon of engineering geology as a branch of modern sciences. Through the engineering geological observation,judg-ment,evaluation,prediction and decision making,the core value of engineering geology can be realized. In the en-gineering geological work the theory and methodology of geology and the identification of engineering geology should be implemented and be promoted,but the advanced theoretical and technology of relevant sciences should be ap-plied to achieve new advancement of engineering geology in serving the reconstruction of the country.
2007, 15(S2): 7-12.
Rock weathering is an common geolgoical phenomenon. There are many results of studies of them, but the results of the quantity study of rock weathering velocity is very few, In fact, studies of preservation of rock cultural relics in a long-term and studies of stability for rock engineering for long-time and so on all need its support, beacuse it is very difficult to last a engugh long-term to make a test of rock weathering under natural condition, perhaps. Importance of studies of rock weathering velocity will be discussed and relevant study meathods will be posed in this paper the push the study of the new problem.
Rock weathering is an common geolgoical phenomenon. There are many results of studies of them, but the results of the quantity study of rock weathering velocity is very few, In fact, studies of preservation of rock cultural relics in a long-term and studies of stability for rock engineering for long-time and so on all need its support, beacuse it is very difficult to last a engugh long-term to make a test of rock weathering under natural condition, perhaps. Importance of studies of rock weathering velocity will be discussed and relevant study meathods will be posed in this paper the push the study of the new problem.
2007, 15(S2): 13-18.
Fault rocks are a special kind of rocks which are formed from original rocks under the dynamic metamorphism (fracture action). They have dramatic characteristics such as belt distribution, limited width, unsteady spatial distribution, cataclastic or scattered structure, and notable effect induced by the exogenic dynamic geological processes etc. The quantity of these rocks is less, but their distribution is broad. The engineering geological properties of these faults are controlled by the fault rocks. Fault gouges have the worst engineering geology properties among fault rocks .The study of fault rocks is an important topics in basic theories of engineering geology.
Fault rocks are a special kind of rocks which are formed from original rocks under the dynamic metamorphism (fracture action). They have dramatic characteristics such as belt distribution, limited width, unsteady spatial distribution, cataclastic or scattered structure, and notable effect induced by the exogenic dynamic geological processes etc. The quantity of these rocks is less, but their distribution is broad. The engineering geological properties of these faults are controlled by the fault rocks. Fault gouges have the worst engineering geology properties among fault rocks .The study of fault rocks is an important topics in basic theories of engineering geology.
2007, 15(S2): 19-25.
Shear strength parameters of rock joints are the important indexes on stability analysis of rock engineering and design of treatment scheme. Rock joint roughness coefficient features i.e. anisomerism, anisotropy, inhomogeneity and scale effect were summarized systematically in the paper. The development of measuring apparatus and technology on rock joint roughness coefficient were retrospected. Detailed procedure of comprehensive evaluation method on rock joint shear strength was introduced. The reliability of comprehensive evaluation method on rock joint shear strength was analyzed by analyzing the shear tests.
Shear strength parameters of rock joints are the important indexes on stability analysis of rock engineering and design of treatment scheme. Rock joint roughness coefficient features i.e. anisomerism, anisotropy, inhomogeneity and scale effect were summarized systematically in the paper. The development of measuring apparatus and technology on rock joint roughness coefficient were retrospected. Detailed procedure of comprehensive evaluation method on rock joint shear strength was introduced. The reliability of comprehensive evaluation method on rock joint shear strength was analyzed by analyzing the shear tests.
2007, 15(S2): 26-32.
Based On the block theory, the author analyses granite rock mass stability of the large underground pe-troleum storage cavens, identifies the location, size and number of the unstable blocks, propose material support scheme to solve partial stabilitv kev technologies question.
Based On the block theory, the author analyses granite rock mass stability of the large underground pe-troleum storage cavens, identifies the location, size and number of the unstable blocks, propose material support scheme to solve partial stabilitv kev technologies question.
2007, 15(S2): 33-37.
The Qinghai-Tibet Railway, completed on 1th July, 2006, greatly contributes to the development and understanding of the Tibet, deeply influences on China and others world, and has historic significance, social effect, politics sense and economic meaning for Chinese modernization construction and the development of the Midwest regional. Many factors affect railway trend scheme, and the most important factor is engineering geology condition on all the railway lines. By comparing with Qinghai-Tibet project, Gansu-Tibet project, Sichuan-Tibet project and Yunnan-Tibet project, it is believed to adopt Qinghai-Tibet project. Qinghai-Tibet Railway,the highest railway above sea level, was confronted with three main difficult problems: permafrost,high-cold and oxygen deficit and ecologic frangibility. Permafrost is the key problem, and it decides whether the Qinghai-Tibet Railway can successfully construct and whether its quality is high. Several generations exerting the most efforts, the Qinghai-Tibet Railway is all right open to traffic. Through retrospecting siting process and construction course, the author realizes hardship of constructing the Qinghai-Tibet Railway and importance of engineering geology.
The Qinghai-Tibet Railway, completed on 1th July, 2006, greatly contributes to the development and understanding of the Tibet, deeply influences on China and others world, and has historic significance, social effect, politics sense and economic meaning for Chinese modernization construction and the development of the Midwest regional. Many factors affect railway trend scheme, and the most important factor is engineering geology condition on all the railway lines. By comparing with Qinghai-Tibet project, Gansu-Tibet project, Sichuan-Tibet project and Yunnan-Tibet project, it is believed to adopt Qinghai-Tibet project. Qinghai-Tibet Railway,the highest railway above sea level, was confronted with three main difficult problems: permafrost,high-cold and oxygen deficit and ecologic frangibility. Permafrost is the key problem, and it decides whether the Qinghai-Tibet Railway can successfully construct and whether its quality is high. Several generations exerting the most efforts, the Qinghai-Tibet Railway is all right open to traffic. Through retrospecting siting process and construction course, the author realizes hardship of constructing the Qinghai-Tibet Railway and importance of engineering geology.
2007, 15(S2): 38-44.
The conditions, process and mechanisem for the step formation are given in the paper. According to the nolinear relationship between displacement of a elastic body and its size derived under the action of its body forces from the similarity theory, an expression between size of a fault step and its active length is derived for the case of plane strain. Attempts to confirm this quantitative relationship by modelling specific examples numerically and physically is made by the authors and analysis of the results of these studies is given in the paper.
The conditions, process and mechanisem for the step formation are given in the paper. According to the nolinear relationship between displacement of a elastic body and its size derived under the action of its body forces from the similarity theory, an expression between size of a fault step and its active length is derived for the case of plane strain. Attempts to confirm this quantitative relationship by modelling specific examples numerically and physically is made by the authors and analysis of the results of these studies is given in the paper.
THE INFLUENCE OF CAVERN'S STRUCTURES ON THE LONG-TERM STABILITY OF LONGYOU LARGE UNDERGROUND CAVERNS
2007, 15(S2): 45-53.
Longyou Caverns,excavated in politic siltstone near ground surface,are with large span,little support area and long-term stability. According to the modern rock mechanics,the caverns can not keep their stability for thousand years,which evokes more and more attentions from many researchers. The aim of the paper is to reveal the mechanism of the long-stability of the caverns. The caverns are all with inclined roofs trending north. The side-walls,especially the east and west-sidewall both incline to inside of the cavern rather than the vertical ones. The rock pillars are all with iron-shape cross sections. Moreover, there is an arcual support upper part of each rock pil-lar. Are the special structures as mentioned above done by chance or designed elaborately? Is the special structure the governing factor making the cavern be integrity for thousand years? The aim of this paper is to answer these questions by numerical computations,which will reveal the mechanism of the long-term stability of Longyou Cav-erns. The numerical analysis results show that the design of inclined roof can solve the problem of shallow-bury,the iron-shaped rock pillar and the upper part arcual support benefit for the stability of the cavern. The design of in-dined sidewall is favorable to the stresses distribution of the surrounding rock. Then,the conclusion can be drawn from the above study that the special structure is the governing factor making the caverns is in their integrities for long-term stability.
Longyou Caverns,excavated in politic siltstone near ground surface,are with large span,little support area and long-term stability. According to the modern rock mechanics,the caverns can not keep their stability for thousand years,which evokes more and more attentions from many researchers. The aim of the paper is to reveal the mechanism of the long-stability of the caverns. The caverns are all with inclined roofs trending north. The side-walls,especially the east and west-sidewall both incline to inside of the cavern rather than the vertical ones. The rock pillars are all with iron-shape cross sections. Moreover, there is an arcual support upper part of each rock pil-lar. Are the special structures as mentioned above done by chance or designed elaborately? Is the special structure the governing factor making the cavern be integrity for thousand years? The aim of this paper is to answer these questions by numerical computations,which will reveal the mechanism of the long-term stability of Longyou Cav-erns. The numerical analysis results show that the design of inclined roof can solve the problem of shallow-bury,the iron-shaped rock pillar and the upper part arcual support benefit for the stability of the cavern. The design of in-dined sidewall is favorable to the stresses distribution of the surrounding rock. Then,the conclusion can be drawn from the above study that the special structure is the governing factor making the caverns is in their integrities for long-term stability.
2007, 15(S2): 54-59.
The parameters of anchoring bolt are very important for anchoring effects. Orthogonal optimum design is an effective method for anchoring bolt. Anchoring parameters of slope of Dawu section in Jingzhu high way are selected using orthogonal design principle. The results show that the effects of anchoring parameters are different and remarkable according to horizontal deformation of slope. The order of the difference is: the effect of anchoring bolt length the interval of anchoring bolt thickness of sprayed concrete. The optimum parameters, i.e. it's the length of the anchoring of 3 m, the interval of the anchoring of 2 m and the thickness of concrete of 100 mm, are obtained.
The parameters of anchoring bolt are very important for anchoring effects. Orthogonal optimum design is an effective method for anchoring bolt. Anchoring parameters of slope of Dawu section in Jingzhu high way are selected using orthogonal design principle. The results show that the effects of anchoring parameters are different and remarkable according to horizontal deformation of slope. The order of the difference is: the effect of anchoring bolt length the interval of anchoring bolt thickness of sprayed concrete. The optimum parameters, i.e. it's the length of the anchoring of 3 m, the interval of the anchoring of 2 m and the thickness of concrete of 100 mm, are obtained.
2007, 15(S2): 60-67.
The paper briefly introduces two types of commonly concerned engineering geological and rock mechani-cal problems of high slopes in hydropower projects under high geostress,1. e.,the baffling large scale relax deform-anon of rock slope at the Jinping No. 1 hydropower station and the fast unloading fractures caused by dam foundation excavation at the Xiaowan hydropower station. The following opinions are presented:①the large scale relax de-formation of the slope at Jinping is actually the result of unloading of the composite stress field of gravity and tecton-is elements,and the large scale,steep slope and strong horizontal tectonic stress are the main factors to enlarge the range of relax deformation.②The phenomena such as thin-tabulate fractures,arciform broken-off andshallot-skin like fractures of fresh hard rock at the excavated surface of dam foundation are caused by unloading of 3 which is almost perpendicular to the slope surface,1. e.,the increase of the difference of principal stresses leads to the rapid failure of rock. As a feature of this kind of rapid unloading relax deformation,the new cracks concentrativelv distributed in the depth of 5~6m near the surface.
The paper briefly introduces two types of commonly concerned engineering geological and rock mechani-cal problems of high slopes in hydropower projects under high geostress,1. e.,the baffling large scale relax deform-anon of rock slope at the Jinping No. 1 hydropower station and the fast unloading fractures caused by dam foundation excavation at the Xiaowan hydropower station. The following opinions are presented:①the large scale relax de-formation of the slope at Jinping is actually the result of unloading of the composite stress field of gravity and tecton-is elements,and the large scale,steep slope and strong horizontal tectonic stress are the main factors to enlarge the range of relax deformation.②The phenomena such as thin-tabulate fractures,arciform broken-off andshallot-skin like fractures of fresh hard rock at the excavated surface of dam foundation are caused by unloading of 3 which is almost perpendicular to the slope surface,1. e.,the increase of the difference of principal stresses leads to the rapid failure of rock. As a feature of this kind of rapid unloading relax deformation,the new cracks concentrativelv distributed in the depth of 5~6m near the surface.
2007, 15(S2): 68-71.
The rock mass physical and mechanical parameters, which are necessary to evaluate the rock mass integrity and strengthen the scarp rock mass of big Buddha, are obtained with elastic wave test method. Analyzing the integrity parameter of Kv, it is discovered that the value of the integrity index of rock mass Kv is bigger than 1 in some part of the terranes. This paper discusses the reason and puts forward the referenced advices for forward correcting the formula of the Integrity index of rock mass.
The rock mass physical and mechanical parameters, which are necessary to evaluate the rock mass integrity and strengthen the scarp rock mass of big Buddha, are obtained with elastic wave test method. Analyzing the integrity parameter of Kv, it is discovered that the value of the integrity index of rock mass Kv is bigger than 1 in some part of the terranes. This paper discusses the reason and puts forward the referenced advices for forward correcting the formula of the Integrity index of rock mass.
2007, 15(S2): 72-83.
Essential features and stability on Badashan Landslide in eastern Qinghai province and its impacts on power transmission line safety are elaborated and analysed qualitatively. It is indicated that the landslide is not a holistic one, but a landslide group, and its stability is controlled by sliding surface shape.
Essential features and stability on Badashan Landslide in eastern Qinghai province and its impacts on power transmission line safety are elaborated and analysed qualitatively. It is indicated that the landslide is not a holistic one, but a landslide group, and its stability is controlled by sliding surface shape.
2007, 15(S2): 84-97.
According to the established GPS monitoring system in Jinchuan No.2 mine, and the real-time monitoring of the ground movement induced by underground mining, the ground movement and deformation characteristics is analyzed according to the large amounts of monitoring data between 2001 and 2006.Based on this, the general transmission mode and presentation attributes of rock movement induced by mining the rapid incline metal mine is expatiated and the mechanism of ground movement is analyzed combined with the numerical simulation and the GPS monitoring results, meanwhile the developmental characters of ground movement velocity is discussed.
According to the established GPS monitoring system in Jinchuan No.2 mine, and the real-time monitoring of the ground movement induced by underground mining, the ground movement and deformation characteristics is analyzed according to the large amounts of monitoring data between 2001 and 2006.Based on this, the general transmission mode and presentation attributes of rock movement induced by mining the rapid incline metal mine is expatiated and the mechanism of ground movement is analyzed combined with the numerical simulation and the GPS monitoring results, meanwhile the developmental characters of ground movement velocity is discussed.
2007, 15(S2): 98-108.
Jiaozhou Bay and its adjacent area are getting more and more important in the economic and social development of Tsingtao city. Based on the understanding of the regional geology around Tsingtao district, the influential factors to stability of the structure, the ground and the rock and soil mass of this area are roundly analyzed and evaluated by analytic hierarchy process. The stabilities of land and offshore areas are respectively evaluated with grey-fuzzy comprehensive evaluation method. In the light of the analysis results, the subareas with different stability levels are distinguished.
Jiaozhou Bay and its adjacent area are getting more and more important in the economic and social development of Tsingtao city. Based on the understanding of the regional geology around Tsingtao district, the influential factors to stability of the structure, the ground and the rock and soil mass of this area are roundly analyzed and evaluated by analytic hierarchy process. The stabilities of land and offshore areas are respectively evaluated with grey-fuzzy comprehensive evaluation method. In the light of the analysis results, the subareas with different stability levels are distinguished.
2007, 15(S2): 109-116.
In this paper, the characteristics of geological and geotechnical engineering monitoring and the shortcomings of conventional monitoring technologies and methods are analyzed, and the connotation of distributed monitoring is defined, the types of fiber optical sensing (FOS) monitoring technologies are introduced, and especially the performance, type and domestic and international progress of distributed FOS technologies are presented, and finally the key technical issues for further research and development are proposed.
In this paper, the characteristics of geological and geotechnical engineering monitoring and the shortcomings of conventional monitoring technologies and methods are analyzed, and the connotation of distributed monitoring is defined, the types of fiber optical sensing (FOS) monitoring technologies are introduced, and especially the performance, type and domestic and international progress of distributed FOS technologies are presented, and finally the key technical issues for further research and development are proposed.
2007, 15(S2): 117-121.
Soft soil widely distributes in our country,and is often consolidated by cement in the progress of progress of foundation treatment.However, great difference exits in consolidation effect,and even some instahle projects occurs in some soft soil area with high organic content. Therefore the technique of scanning electronic microscope(SEM) is used to study the consolidation effect of cement. On the basis of soil microstructure .the granular metric.compo-nent of structure unit, pore feature and structural feature of cement treated soil with high organic content in same part of highway in JiangMen is quantitatively analyzed. The quantitative results of SEM picture show that as to the studied cement treated soil,the directing property of structure unit and pore is poor, more micro and small pores are developed in particles,and all the samples are isotropic.
Soft soil widely distributes in our country,and is often consolidated by cement in the progress of progress of foundation treatment.However, great difference exits in consolidation effect,and even some instahle projects occurs in some soft soil area with high organic content. Therefore the technique of scanning electronic microscope(SEM) is used to study the consolidation effect of cement. On the basis of soil microstructure .the granular metric.compo-nent of structure unit, pore feature and structural feature of cement treated soil with high organic content in same part of highway in JiangMen is quantitatively analyzed. The quantitative results of SEM picture show that as to the studied cement treated soil,the directing property of structure unit and pore is poor, more micro and small pores are developed in particles,and all the samples are isotropic.
2007, 15(S2): 122-127.
Ground subsidence is the major geologic disaster of coastal city in the world, which has brought about serious loss to the economy. Ground subsidence occurs when large amounts of groundwater have been withdrawn from certain types of rocks, such as fine-grained sediments. How to reduce the damage extent and to control the ground subsidence is a hot topic, which is closely related to the national economy and the public livelihood. In this paper, further studies in the field are pointed out.
Ground subsidence is the major geologic disaster of coastal city in the world, which has brought about serious loss to the economy. Ground subsidence occurs when large amounts of groundwater have been withdrawn from certain types of rocks, such as fine-grained sediments. How to reduce the damage extent and to control the ground subsidence is a hot topic, which is closely related to the national economy and the public livelihood. In this paper, further studies in the field are pointed out.
2007, 15(S2): 128-133.
Free shrinkage ratio of Mengzi expansive soil is measured under different water content and dry density with micrometer. Shrinkage characteristic of expansive soil has no direct connection with dry density. The larger the water content of the sample, the stronger the anisotropy. The higher water content of the sample, the greater the shrinkage . The quantitative relationship between water content and linear shrinkage ratio is gained under different dry density for Mengzi expansive soil, which has great value to engineering practice.
Free shrinkage ratio of Mengzi expansive soil is measured under different water content and dry density with micrometer. Shrinkage characteristic of expansive soil has no direct connection with dry density. The larger the water content of the sample, the stronger the anisotropy. The higher water content of the sample, the greater the shrinkage . The quantitative relationship between water content and linear shrinkage ratio is gained under different dry density for Mengzi expansive soil, which has great value to engineering practice.
2007, 15(S2): 134-137.
In order to present scientific conclusion for engineering's foundation soil treatment,the advantage and shortage of different foundation soil treatment methods are studied based on soil condition in situ.
In order to present scientific conclusion for engineering's foundation soil treatment,the advantage and shortage of different foundation soil treatment methods are studied based on soil condition in situ.
2007, 15(S2): 138-141.
Coupling is a very popular term at present, which is applied widely in geotechnical engineering field. In this article, we are going to analyze primarily the concept of coupling and its applied range, moreover generalize and analyze respectively the coupling of the research means, calculating methods, and constitutive relation. Moreover, we point out several samples of the misapplying coupling, and prospect the foreground of its application.
Coupling is a very popular term at present, which is applied widely in geotechnical engineering field. In this article, we are going to analyze primarily the concept of coupling and its applied range, moreover generalize and analyze respectively the coupling of the research means, calculating methods, and constitutive relation. Moreover, we point out several samples of the misapplying coupling, and prospect the foreground of its application.
2007, 15(S2): 142-145.
In order to save cultivated land resources and reduce efficiently the cost of project construction,the sub-grade or borrow pits are placed in low-lying places such as reservoirs and ponds,and soft-soil is used to be road-bed filling materials. With high porosity ratio,high compressibility,high water content and low strength,natural soft soil can not meet needs of projects. If soft soil would not be handled properly,geotechnical engineering prob-lems or engineering accidents would occurred in projects construction. Because of different genesis,the engineering geological properties of soft soils are obviously different. This paper discusses the engineering geological properties and the genetic types of soft soils based on their mineral compositions.
In order to save cultivated land resources and reduce efficiently the cost of project construction,the sub-grade or borrow pits are placed in low-lying places such as reservoirs and ponds,and soft-soil is used to be road-bed filling materials. With high porosity ratio,high compressibility,high water content and low strength,natural soft soil can not meet needs of projects. If soft soil would not be handled properly,geotechnical engineering prob-lems or engineering accidents would occurred in projects construction. Because of different genesis,the engineering geological properties of soft soils are obviously different. This paper discusses the engineering geological properties and the genetic types of soft soils based on their mineral compositions.
2007, 15(S2): 146-150.
Three kinds of improvement method are put forward in the design of expressway embankment for expan-live soil in Hubei province. It is clear that the value of C and is improved in different extent with inforcement by the analysis of slope stability with the software of Geo-slope. Load on the top of embankment can be transferred to the bottom effectively by the geomaterial,which can mitigate the settlement of embankment remarkably. The three methods are reasonable and effective in improving the expansive embankment and can be applied into engineering of expansive soil in a large scale.
Three kinds of improvement method are put forward in the design of expressway embankment for expan-live soil in Hubei province. It is clear that the value of C and is improved in different extent with inforcement by the analysis of slope stability with the software of Geo-slope. Load on the top of embankment can be transferred to the bottom effectively by the geomaterial,which can mitigate the settlement of embankment remarkably. The three methods are reasonable and effective in improving the expansive embankment and can be applied into engineering of expansive soil in a large scale.
2007, 15(S2): 151-154.
The method of flexibility fence is used triumphantly in cutting slope of expansive soil in the expressway in Hubei province. The effect of fence is obvious to all. The parameters are optimized by numerical analysis. The construction technics is generalized normatively that it can be applied to slope engineering of expansive soil widely.
The method of flexibility fence is used triumphantly in cutting slope of expansive soil in the expressway in Hubei province. The effect of fence is obvious to all. The parameters are optimized by numerical analysis. The construction technics is generalized normatively that it can be applied to slope engineering of expansive soil widely.
2007, 15(S2): 155-161.
As the theory and technology of applied Geological Engineering,the culture relic protection Geological Engineering is the science which researches on the geology problems in the process of culture relic protection. It features a series of restriction conditions of the culture relic such as rareness,nonregeneratability,immobility,long time preservation as well as its core objective in service,that is,the authenticity of culture relic and its integrity with the existing environment. This paper not only introduced the characteristics,tasks and contents of the search on culture relic protection Geological Engineering but also put forward the initial suggestions about the culture relic protection Geological Engineering working phase division and the selecting principles of its reconnaissance technolo-gy. In addition,the paper discussed contents,approaches,and section division of environmental research of cul-ture relic protection Geological Engineering.
As the theory and technology of applied Geological Engineering,the culture relic protection Geological Engineering is the science which researches on the geology problems in the process of culture relic protection. It features a series of restriction conditions of the culture relic such as rareness,nonregeneratability,immobility,long time preservation as well as its core objective in service,that is,the authenticity of culture relic and its integrity with the existing environment. This paper not only introduced the characteristics,tasks and contents of the search on culture relic protection Geological Engineering but also put forward the initial suggestions about the culture relic protection Geological Engineering working phase division and the selecting principles of its reconnaissance technolo-gy. In addition,the paper discussed contents,approaches,and section division of environmental research of cul-ture relic protection Geological Engineering.
2007, 15(S2): 162-166.
With the booming of economic and urbanization progress, some vulnerability problems of urban geological environment of Kunming city are presented, some of the problems have been paid the special attention by the government, however some of the problems still did not cause to the necessary attention. There are many problems existed in the city of Kunming, such as, geological disasters, frangible geological phenomena, groundwater quality, environment quality, suitable site for the waste treatment, land resources, water resources etc.. Enough attention must be paid to these problems in the progress of developing and perfecting for the city of Kunming.
With the booming of economic and urbanization progress, some vulnerability problems of urban geological environment of Kunming city are presented, some of the problems have been paid the special attention by the government, however some of the problems still did not cause to the necessary attention. There are many problems existed in the city of Kunming, such as, geological disasters, frangible geological phenomena, groundwater quality, environment quality, suitable site for the waste treatment, land resources, water resources etc.. Enough attention must be paid to these problems in the progress of developing and perfecting for the city of Kunming.
2007, 15(S2): 167-173.
The characteristics of engineering geology environment of Qingdao City are systematically analyzed by using the Analytic Hierarchy Process. The weight of the fifteen index factor affecting the engineering geo-environmental quality can be ascertained through determining the nature and calculation, and the results are more reasonable and scientific. The Fuzzy mathematics, a powerful tool dealing with the fuzzy problems, has been comprehensively used to evaluate the engineering geo-environmental quality of the main functional zone of Qingdao City, and the evaluation map of the urban engineering geo-environmental quality of the main functional zone of Qingdao City can be the basis of engineering construction plan and economic development's arrangement.
The characteristics of engineering geology environment of Qingdao City are systematically analyzed by using the Analytic Hierarchy Process. The weight of the fifteen index factor affecting the engineering geo-environmental quality can be ascertained through determining the nature and calculation, and the results are more reasonable and scientific. The Fuzzy mathematics, a powerful tool dealing with the fuzzy problems, has been comprehensively used to evaluate the engineering geo-environmental quality of the main functional zone of Qingdao City, and the evaluation map of the urban engineering geo-environmental quality of the main functional zone of Qingdao City can be the basis of engineering construction plan and economic development's arrangement.
2007, 15(S2): 174-178.
Based on the field investigation and previous studies, the paper describes the hydrogeological characteristics and groundwater circulation in Beishan area, Gansu province, one potential site for high-level radioactive nuclear waste disposal of China . The regional groundwater flow pattern is discussed on recharge characteristics, discharge paths and boundary conditions.
Based on the field investigation and previous studies, the paper describes the hydrogeological characteristics and groundwater circulation in Beishan area, Gansu province, one potential site for high-level radioactive nuclear waste disposal of China . The regional groundwater flow pattern is discussed on recharge characteristics, discharge paths and boundary conditions.
2007, 15(S2): 179-183.
The leakage of reservoir is a principal engineering geological problem of Manghekou Reservoir, Jiyuan City, Henan Province, China. A qualitative study on the probable karst leakage path of Manghekou Reservoir is given. According to the nesting model which has three kinds of scale (watershed, reservoir zone and dam region) and 3D numerical simulation technology, 3D numerical groundwater seepage flow model is built in dam region. The change of seepage flow field, the capacity of leakage and the effect of anti seepage are predicted after the reservoir completed. These provide scientific basis for the design and construction of watertight curtain.
The leakage of reservoir is a principal engineering geological problem of Manghekou Reservoir, Jiyuan City, Henan Province, China. A qualitative study on the probable karst leakage path of Manghekou Reservoir is given. According to the nesting model which has three kinds of scale (watershed, reservoir zone and dam region) and 3D numerical simulation technology, 3D numerical groundwater seepage flow model is built in dam region. The change of seepage flow field, the capacity of leakage and the effect of anti seepage are predicted after the reservoir completed. These provide scientific basis for the design and construction of watertight curtain.
2007, 15(S2): 184-187.
The research of strain-softening is a hot topic in engineering. Currently, the constitutive model for the strain-softening medium is described by negative exponent distribution or the Weibull's distribution law. However, there is few researche on how to get the parameters of the model. In this paper, parameters of the constitutive relation are solved.
The research of strain-softening is a hot topic in engineering. Currently, the constitutive model for the strain-softening medium is described by negative exponent distribution or the Weibull's distribution law. However, there is few researche on how to get the parameters of the model. In this paper, parameters of the constitutive relation are solved.
2007, 15(S2): 188-192.
The researches on the stability of slope by strength reduction mainly refer to homogeneous slopes, however, when the inhomogeneous slopes are met, some questions will come forth, the scope of strength reduction is global or local region? In view of the above, the global strength reduction and the local strength reduction are programmed in this paper by FISH in the FLAC3D, and the inhomogeneous slopes are analyzed. The results show that the safety factors of inhomogeneous slope solved by these two methods are not always equal and the factor of safety computed by global strength reduction is more reasonable and more precise, so it is advised that the global strength method is better than the local strength method when the inhomogeneous slope is analyzed.
The researches on the stability of slope by strength reduction mainly refer to homogeneous slopes, however, when the inhomogeneous slopes are met, some questions will come forth, the scope of strength reduction is global or local region? In view of the above, the global strength reduction and the local strength reduction are programmed in this paper by FISH in the FLAC3D, and the inhomogeneous slopes are analyzed. The results show that the safety factors of inhomogeneous slope solved by these two methods are not always equal and the factor of safety computed by global strength reduction is more reasonable and more precise, so it is advised that the global strength method is better than the local strength method when the inhomogeneous slope is analyzed.
2007, 15(S2): 193-196.
Based on upper bound theorem of energy method,and concerning the sliding body of soil slope as deformable body,the calculation formula can be deduced according to proper combination of energy method strength reduction method. The difference between energy method and traditional rigid limit equilibrium method shows in two aspects:firstly the former uses energy balance,whereas the latter uses static balance;secondly,the former treats sliding body as deformable body,whereas the latter treats sliding body as rigid body. Through a typi-cal case study,the calculation results show that the safety factor of energy method is smaller than rigid limit equilib-rium method.
Based on upper bound theorem of energy method,and concerning the sliding body of soil slope as deformable body,the calculation formula can be deduced according to proper combination of energy method strength reduction method. The difference between energy method and traditional rigid limit equilibrium method shows in two aspects:firstly the former uses energy balance,whereas the latter uses static balance;secondly,the former treats sliding body as deformable body,whereas the latter treats sliding body as rigid body. Through a typi-cal case study,the calculation results show that the safety factor of energy method is smaller than rigid limit equilib-rium method.
2007, 15(S2): 197-202.
In the field work of control一source magnetotelluric method,the space between the transmitter and the receiver is more than 3~5 times skin depth,so it is important to study the impact of the abnormal body in this area on the target body in the exploration area. In this paper, to a line source,the impact of the abnormal body out of exploration area with different resistivity,size and location on the target body in the exploration area is discussed with 2D finite element method(FEM ).Through the study,it can be concluded that if the abnormal body out of the exploration area is a conductor,the lower the resistivity,the larger the impact on the exploration area;the larger its size,the larger the impact;the shallower its buried,the larger the impact range;the deeper its buried depth,the smaller the impact on the body in the shallow exploration area,but its impact is almost same as what the shallow one has. When the abnormal body is resistive,the similar effect rules can be obtained,but the impact is very small.
In the field work of control一source magnetotelluric method,the space between the transmitter and the receiver is more than 3~5 times skin depth,so it is important to study the impact of the abnormal body in this area on the target body in the exploration area. In this paper, to a line source,the impact of the abnormal body out of exploration area with different resistivity,size and location on the target body in the exploration area is discussed with 2D finite element method(FEM ).Through the study,it can be concluded that if the abnormal body out of the exploration area is a conductor,the lower the resistivity,the larger the impact on the exploration area;the larger its size,the larger the impact;the shallower its buried,the larger the impact range;the deeper its buried depth,the smaller the impact on the body in the shallow exploration area,but its impact is almost same as what the shallow one has. When the abnormal body is resistive,the similar effect rules can be obtained,but the impact is very small.
2007, 15(S2): 203-207.
Geothermal exploration in urban and suburban Beijing areas is a challenging task because of the high-level ambient noises. The paper summarizes several successful applications of the CSAMT method to geothermal exploration in the Beijing area. By carefully selecting the output power, operating frequency, transmitter length, and receiver spacing, we were able to accurately locate geothermal reservoirs deeper than 2000 meters. In the Beijing area, the CSAMT is particularly useful in locating hot-water-bearing faults.
Geothermal exploration in urban and suburban Beijing areas is a challenging task because of the high-level ambient noises. The paper summarizes several successful applications of the CSAMT method to geothermal exploration in the Beijing area. By carefully selecting the output power, operating frequency, transmitter length, and receiver spacing, we were able to accurately locate geothermal reservoirs deeper than 2000 meters. In the Beijing area, the CSAMT is particularly useful in locating hot-water-bearing faults.
2007, 15(S2): 208-212.
An hydropower station is located in carbonate rock area. Where Karst strongly develops, hydrogeologic conditions are extremly complex. The Karst seepage is the key issues which restrict the construction of the hydropower station. In order to detect the distribution of groundwater and concealed karst, the authors used EH4 magnetotelluric sounding system for the survey work. And the authors had detect 10 Karst and three faults. At the end of the paper, the conclusion was put forward that the reservoir will success after the karst leakage locations be well treated.
An hydropower station is located in carbonate rock area. Where Karst strongly develops, hydrogeologic conditions are extremly complex. The Karst seepage is the key issues which restrict the construction of the hydropower station. In order to detect the distribution of groundwater and concealed karst, the authors used EH4 magnetotelluric sounding system for the survey work. And the authors had detect 10 Karst and three faults. At the end of the paper, the conclusion was put forward that the reservoir will success after the karst leakage locations be well treated.
2007, 15(S2): 213-217.
In geophysical exploration work on bad geologic body of deep-long tunnel, controlled source audio frequency magnetotellurics method (CSAMT) is fairly effective one of detecting such bad geologic bodies. However, CSAMT data is affected badly by static effect in complex terrain, and whether the effect of static correction is good or not is crucial for interpretation results. Based on reviewing the relative references on static correction this paper presents a correction method of EMAP method combined with all profile comparison method. Then a case study has been carried out in one revised railway tunnel of southwestern China, and the result is well verified by boreholes and relative geologic information, which indicates that this corection method is effective in CSAMT data processing, and CSAMT method is feasible for analysis of rock property of tunnel line. Therefore CSAMT method is an instructive guide for tunnel digging.
In geophysical exploration work on bad geologic body of deep-long tunnel, controlled source audio frequency magnetotellurics method (CSAMT) is fairly effective one of detecting such bad geologic bodies. However, CSAMT data is affected badly by static effect in complex terrain, and whether the effect of static correction is good or not is crucial for interpretation results. Based on reviewing the relative references on static correction this paper presents a correction method of EMAP method combined with all profile comparison method. Then a case study has been carried out in one revised railway tunnel of southwestern China, and the result is well verified by boreholes and relative geologic information, which indicates that this corection method is effective in CSAMT data processing, and CSAMT method is feasible for analysis of rock property of tunnel line. Therefore CSAMT method is an instructive guide for tunnel digging.
2007, 15(S2): 218-222.
In order to identify the overburden thickness,the distribution of weathering crust zone,weathering cap-sule and fractured zone,and to subdivide unfavorable geological condition within a tunnel,the authors use CSAMT method in the survey work. Because the surveyed area closes to the power station and its large substation,electro-magnetic interference is very strong,and the data obtained is not good. In order to improve the inversion precision,the genetic algorithms(GA ) inversion method is introduced. The inversion result by GA is much better than the re-cult reached by linear inversion method.
In order to identify the overburden thickness,the distribution of weathering crust zone,weathering cap-sule and fractured zone,and to subdivide unfavorable geological condition within a tunnel,the authors use CSAMT method in the survey work. Because the surveyed area closes to the power station and its large substation,electro-magnetic interference is very strong,and the data obtained is not good. In order to improve the inversion precision,the genetic algorithms(GA ) inversion method is introduced. The inversion result by GA is much better than the re-cult reached by linear inversion method.
2007, 15(S2): 223-226.
SAMT method has been developed since middle 1980's, is featured by its high sensitivity, large depth of detection, and strong ability against interference, and be widely used in prospecting resources and bad geologic body. The principles of CSAMT method are introduced simplly, and CSAMT method has been applied to explore cavity in gold mine of Tibet. Based on relative geologic information, geologic interpretation has been given for measured mine, and the prospective ore-bearing zone has been carved up for further gold exploration.
SAMT method has been developed since middle 1980's, is featured by its high sensitivity, large depth of detection, and strong ability against interference, and be widely used in prospecting resources and bad geologic body. The principles of CSAMT method are introduced simplly, and CSAMT method has been applied to explore cavity in gold mine of Tibet. Based on relative geologic information, geologic interpretation has been given for measured mine, and the prospective ore-bearing zone has been carved up for further gold exploration.
2007, 15(S2): 227-232.
There are large areas buried Karst distribution in China. Therefore,it has great significance on engi-neering constructions that launch the geophysical exploration study in limestone karst strongly developed area such as on tunnel projects. CSAMT method is effective to detect lays at required depth for projects. In this paper CSAMT method was applied on a railway tunnel in limestone karst strongly developed area in Guizhou province. The basic theory of CSAMT method was introduced,and the property of data acquisition correspond to actual situation was de-scribed,and then the methods of processing and interpretation on data influenced by terrain effect and static effect were represented. Geological interpretation was made based on the comparison between analyzed original curves and inversion results,combined the geological information of Study area also. Finally,the harmful zone to project are plotted out. Meanwhile,the corresponding recommendations are propounded.
There are large areas buried Karst distribution in China. Therefore,it has great significance on engi-neering constructions that launch the geophysical exploration study in limestone karst strongly developed area such as on tunnel projects. CSAMT method is effective to detect lays at required depth for projects. In this paper CSAMT method was applied on a railway tunnel in limestone karst strongly developed area in Guizhou province. The basic theory of CSAMT method was introduced,and the property of data acquisition correspond to actual situation was de-scribed,and then the methods of processing and interpretation on data influenced by terrain effect and static effect were represented. Geological interpretation was made based on the comparison between analyzed original curves and inversion results,combined the geological information of Study area also. Finally,the harmful zone to project are plotted out. Meanwhile,the corresponding recommendations are propounded.
2007, 15(S2): 233-236.
The general constitute and elementary content of GIS-based high-slope intelligent prediction system of Jinping first-level hydropower station are introduced,which is beneficial to the long-term monitoring and predic-tion during the building and running of hydropower station.
The general constitute and elementary content of GIS-based high-slope intelligent prediction system of Jinping first-level hydropower station are introduced,which is beneficial to the long-term monitoring and predic-tion during the building and running of hydropower station.
2007, 15(S2): 237-241.
Because of complexity of the regional landslide hazard assessment, the relation between known variants and unknown ones is very strong nonlinear. The BP neural network has high non-linear mapping capacity, and a good result can be obtained with BP neural network to analyze the regional landslide hazard. The paper creates BP neural network by use of Matlab neural network toolbox,combining regional landslide hazard assessment, to examine and predict hazard of regional landslide.
Because of complexity of the regional landslide hazard assessment, the relation between known variants and unknown ones is very strong nonlinear. The BP neural network has high non-linear mapping capacity, and a good result can be obtained with BP neural network to analyze the regional landslide hazard. The paper creates BP neural network by use of Matlab neural network toolbox,combining regional landslide hazard assessment, to examine and predict hazard of regional landslide.
2007, 15(S2): 242-245.
Base on the geological model in a Highway tunnel, the size effect and the exterior loading direction effect of rock mass in the tunnel are analyzed with 3DEC. Uniaxial compression test and triaxial compression test are simulated to calculate mechanical parameters of rock mass. The calculating mechanical parameters of rock mass are the integrated result of the rock, structures and surroundings. This method is a paradigm of calculation mechanical parameters of rock mass with 3DEC.
Base on the geological model in a Highway tunnel, the size effect and the exterior loading direction effect of rock mass in the tunnel are analyzed with 3DEC. Uniaxial compression test and triaxial compression test are simulated to calculate mechanical parameters of rock mass. The calculating mechanical parameters of rock mass are the integrated result of the rock, structures and surroundings. This method is a paradigm of calculation mechanical parameters of rock mass with 3DEC.
2007, 15(S2): 246-252.
Under the condition of the excavation changing from open pit into underground mine, the predictions of the ground surface displacement and the stability of slope is always the significant technology problem. In view of the insufficiency of the present prediction methods, the FLAC is used to simulate gradual excavation of No.B902 mine in Antaibao coal mine. From the case, the law of ground surface displacement is summarized, the value of displacement is predicted, and the stability of slope is analyzed. By comparing the monitoring data with the simulation results, it is shown that the FLAC is a simple and effective way to predict the ground displacement and analysis the stability of slope based on the actual physical mechanics parameters under the condition of the excavation changing from open pit into underground mine.
Under the condition of the excavation changing from open pit into underground mine, the predictions of the ground surface displacement and the stability of slope is always the significant technology problem. In view of the insufficiency of the present prediction methods, the FLAC is used to simulate gradual excavation of No.B902 mine in Antaibao coal mine. From the case, the law of ground surface displacement is summarized, the value of displacement is predicted, and the stability of slope is analyzed. By comparing the monitoring data with the simulation results, it is shown that the FLAC is a simple and effective way to predict the ground displacement and analysis the stability of slope based on the actual physical mechanics parameters under the condition of the excavation changing from open pit into underground mine.
2007, 15(S2): 253-256.
The objective of this research is to obtain more subsurface lithologic information such as anisotropic,in-elastic parameters than onventional processing,by using the finite-element least-squares inversion in frequency domain,which is very helpful to direct detection or depiction of oil or gas reservoir, etc. Since to invert all the 1ithologic coefficients including anisotropic,inelastic directly is very nonlinear and difficult,we first select some sim-ple parameters to invert,such as P-wave and S-wave velocities,which can obtain more lithologic information:S-wave velocity than conventional acoustic-wave inversion.We deduce the formula of the finite-element least-squares inversion on the basis of forward modeling equations according to minimum of square roots of data residuals between field and calculation. We apply several advanta-genus methods,such as applying the compressional matrix-storage and LU-decomposition techniques to save and solve the large sparse complex-valued coefficient matrix,applying Green functions to solve the Jacobi coefficients in inversion fast,using the conjugate-gradient method to solve unknowns.
The objective of this research is to obtain more subsurface lithologic information such as anisotropic,in-elastic parameters than onventional processing,by using the finite-element least-squares inversion in frequency domain,which is very helpful to direct detection or depiction of oil or gas reservoir, etc. Since to invert all the 1ithologic coefficients including anisotropic,inelastic directly is very nonlinear and difficult,we first select some sim-ple parameters to invert,such as P-wave and S-wave velocities,which can obtain more lithologic information:S-wave velocity than conventional acoustic-wave inversion.We deduce the formula of the finite-element least-squares inversion on the basis of forward modeling equations according to minimum of square roots of data residuals between field and calculation. We apply several advanta-genus methods,such as applying the compressional matrix-storage and LU-decomposition techniques to save and solve the large sparse complex-valued coefficient matrix,applying Green functions to solve the Jacobi coefficients in inversion fast,using the conjugate-gradient method to solve unknowns.