1998 Vol. 6, No. 2
1998, 6(2): 97-102.
he geological structure of the paleo landslide system in the new site of Wushan is analyzed in the paper and the besic characteristics of tectonic deformation field for the paleo landslide system are discussed. The features of the landslide structure obviously differ from those of regional structure and are also different in the paleo landslide system. For this reason, it can be used to determine the frontier or the back boundary of the landslide and to probe into the evolution of the slide.
he geological structure of the paleo landslide system in the new site of Wushan is analyzed in the paper and the besic characteristics of tectonic deformation field for the paleo landslide system are discussed. The features of the landslide structure obviously differ from those of regional structure and are also different in the paleo landslide system. For this reason, it can be used to determine the frontier or the back boundary of the landslide and to probe into the evolution of the slide.
1998, 6(2): 103-113.
ijiapo slope is a paleo landslide in Baoji City. Based on inverstigation of hydrogeological and engineering geological factors of the slope, the form and material structure and deformation fracture features of surficial loess body of the slope are described, and the dynamic mechanism for paleo landslide is discussed in this paper. Using Sarma method for slope division in arbitrary way, the stability of the landslide are studied at natural (recent), earthquake and water saturation states or synchronously at three states. And then, its sensitivity analysis is made that stability change of surficial loess body can take plecs with groundwater table rising or lowering. General conclusion is that Dijiapo slope is stable, its surficial loess body will be unstable as groundwater table rising. Eventually, some control ways are put forward to it.
ijiapo slope is a paleo landslide in Baoji City. Based on inverstigation of hydrogeological and engineering geological factors of the slope, the form and material structure and deformation fracture features of surficial loess body of the slope are described, and the dynamic mechanism for paleo landslide is discussed in this paper. Using Sarma method for slope division in arbitrary way, the stability of the landslide are studied at natural (recent), earthquake and water saturation states or synchronously at three states. And then, its sensitivity analysis is made that stability change of surficial loess body can take plecs with groundwater table rising or lowering. General conclusion is that Dijiapo slope is stable, its surficial loess body will be unstable as groundwater table rising. Eventually, some control ways are put forward to it.
1998, 6(2): 114-119.
n the basis of simulation of seismic reflection profiles and field investigation of faults in the Baoquan Hydroelectric Station area, Henan Province, it can be inferred that the faults have ceased to activate since Late Pleistocene and the fault activity will not significantly affect the stability of Baoquan Hydroelectric Station.
n the basis of simulation of seismic reflection profiles and field investigation of faults in the Baoquan Hydroelectric Station area, Henan Province, it can be inferred that the faults have ceased to activate since Late Pleistocene and the fault activity will not significantly affect the stability of Baoquan Hydroelectric Station.
1998, 6(2): 120-127.
n this paper, the factors affecting the satety tickness of roof of shallow underground excavation in Chongqing City are analysied with referencing previous data. The mechanism for failure under the effct of interaction between the foundation and the undergraund excavation, the effect of every factors on the safety tickness of roof and the variability law are studied by means of FEM numerical simulation. The safety thickness of roof forecasting model is obtained by stepwise regression analysis.
n this paper, the factors affecting the satety tickness of roof of shallow underground excavation in Chongqing City are analysied with referencing previous data. The mechanism for failure under the effct of interaction between the foundation and the undergraund excavation, the effect of every factors on the safety tickness of roof and the variability law are studied by means of FEM numerical simulation. The safety thickness of roof forecasting model is obtained by stepwise regression analysis.
1998, 6(2): 128-133.
ccording to the similarity theory and research experience on rock and soil slopes, the change regularities of stress field, displacement field, and medium strength of slope in the size similarity transformation are discussed in the paper. It is proved that with the slope size magnification in similarity scale Cl, the quantity of stresses will be amplified linearly in the same scale, but the shape of stress trace network will keep the same; the displacement will be amplified in a scale ofC 2l, the strength of slope medium will be decreased in a function of inverse proportion with Cl , and the failure surface will be inward shift. It also indicates that while both size and medium change simultaneously, the displacement, strength, and the shape of failure surface will also change in their special regularites. An example is given to prove the theoretical results above. The results will be helpful to research of engineering behavior of high slope.
ccording to the similarity theory and research experience on rock and soil slopes, the change regularities of stress field, displacement field, and medium strength of slope in the size similarity transformation are discussed in the paper. It is proved that with the slope size magnification in similarity scale Cl, the quantity of stresses will be amplified linearly in the same scale, but the shape of stress trace network will keep the same; the displacement will be amplified in a scale ofC 2l, the strength of slope medium will be decreased in a function of inverse proportion with Cl , and the failure surface will be inward shift. It also indicates that while both size and medium change simultaneously, the displacement, strength, and the shape of failure surface will also change in their special regularites. An example is given to prove the theoretical results above. The results will be helpful to research of engineering behavior of high slope.
1998, 6(2): 134-138.
n recent years, in order to study the activities along faults around and in front of the Three Gorges damsite, TL, ESR, FT, and U series dating methods have been use to date Xiannishan and Jiuwanxi faults. However, the obtained age data very scattered, so as to cant use these data. In this paper we suggest that: 1) appropriate time interval for dating methods; 2) back zero condition of samples; 3) implication of age of fault activities; 4) judgement of scattered age date; 5) disturbing factors for dating; 6) interference of geological background in dating results. Understanding the suggested above permits to select proper age data fit to geological background and more exactly evaluate the safety and stability of the Three Gorge Dam.
n recent years, in order to study the activities along faults around and in front of the Three Gorges damsite, TL, ESR, FT, and U series dating methods have been use to date Xiannishan and Jiuwanxi faults. However, the obtained age data very scattered, so as to cant use these data. In this paper we suggest that: 1) appropriate time interval for dating methods; 2) back zero condition of samples; 3) implication of age of fault activities; 4) judgement of scattered age date; 5) disturbing factors for dating; 6) interference of geological background in dating results. Understanding the suggested above permits to select proper age data fit to geological background and more exactly evaluate the safety and stability of the Three Gorge Dam.
1998, 6(2): 139-144.
ateway in inclined coal seam is difficult to maintaine mainly due to its location in a remarkably anisotropic environment. The failure and deformation mechanism and pattern of gateway in inclined seam are analyzed by using discrete element method in combination with measurement of loose zone around gateway in field. It is proved that the upper side wall fails seriously and it is the key part to maintain the whole gateway. It is suggested that a comprehensive support pattern must be adopted including sidewall reinforcing.
ateway in inclined coal seam is difficult to maintaine mainly due to its location in a remarkably anisotropic environment. The failure and deformation mechanism and pattern of gateway in inclined seam are analyzed by using discrete element method in combination with measurement of loose zone around gateway in field. It is proved that the upper side wall fails seriously and it is the key part to maintain the whole gateway. It is suggested that a comprehensive support pattern must be adopted including sidewall reinforcing.
1998, 6(2): 145-149.
This paper discusses the method of selecting the shear parameters of rockmass for Baoquan Pumping Storage Power Station from the data of shear test at the station site. The formulas of numerical characteristics of C and f are derived. The results of comparison and analysis prove that the random fuzzy method is more realistic and appropriate because the shear parameters of rockmass are of the randomness and fuzziness, and the formulas of numerical characteristics suggested in the paper can verify the variation and correlativity of C and f.
This paper discusses the method of selecting the shear parameters of rockmass for Baoquan Pumping Storage Power Station from the data of shear test at the station site. The formulas of numerical characteristics of C and f are derived. The results of comparison and analysis prove that the random fuzzy method is more realistic and appropriate because the shear parameters of rockmass are of the randomness and fuzziness, and the formulas of numerical characteristics suggested in the paper can verify the variation and correlativity of C and f.
1998, 6(2): 150-154.
iscontinuity spacing in rockmass is very important for prediction of rock behaviour. The negative exponential probability distribution density of rock discontinuity spacing based on infinite length scanline measurement is the most important distribution function. A closed form function is proposed for correction of sampling base caused by finite length scanline in this paper. The result shows that the suggested method is quite effective in decreasing relative error percentage, this makes it possible to estimate discontinuity spacing of rockmase using short scanline. It is also of great importance for decreasing the measurement cost.
iscontinuity spacing in rockmass is very important for prediction of rock behaviour. The negative exponential probability distribution density of rock discontinuity spacing based on infinite length scanline measurement is the most important distribution function. A closed form function is proposed for correction of sampling base caused by finite length scanline in this paper. The result shows that the suggested method is quite effective in decreasing relative error percentage, this makes it possible to estimate discontinuity spacing of rockmase using short scanline. It is also of great importance for decreasing the measurement cost.
1998, 6(2): 155-159.
ased on rock slope engineering cases, three experiments on the possibility of use an artificial neural network (ANN) in estimating the safety factors for rock slope are present and discussed in this paper. The experiment results show that estimating the safety factors for rock slope by using a neural network is feasible, real time and accurate. It is very simple for preparatory work.
ased on rock slope engineering cases, three experiments on the possibility of use an artificial neural network (ANN) in estimating the safety factors for rock slope are present and discussed in this paper. The experiment results show that estimating the safety factors for rock slope by using a neural network is feasible, real time and accurate. It is very simple for preparatory work.
1998, 6(2): 160-165.
Basing on the characteristics of regional geological structure of Datong Coal Field, the difinition of the curtian rock (which is a vertical sedimentary vein in coal bed 10 # in Sitai mine of Datong Coal Field), lithologic chracteristics, shape attitude, distribution, and genesis are studied and analyzed in this paper, mean while, It also points out that the curtain rock has genetic relation with para syngenetic karst pillars develped in the mine field.
Basing on the characteristics of regional geological structure of Datong Coal Field, the difinition of the curtian rock (which is a vertical sedimentary vein in coal bed 10 # in Sitai mine of Datong Coal Field), lithologic chracteristics, shape attitude, distribution, and genesis are studied and analyzed in this paper, mean while, It also points out that the curtain rock has genetic relation with para syngenetic karst pillars develped in the mine field.
1998, 6(2): 166-173.
omprehensive fuzzy assessment and zoning of sand liquefaction in 5 counties of the southeastern Weihe basin were performed by using influence factors of sand liquefaction and a lot of actual data. Moreover, the influence of flood on sand liquefaction has also been discussed.
omprehensive fuzzy assessment and zoning of sand liquefaction in 5 counties of the southeastern Weihe basin were performed by using influence factors of sand liquefaction and a lot of actual data. Moreover, the influence of flood on sand liquefaction has also been discussed.
1998, 6(2): 174-180.
ased on the field investigations and from results of chemical experiments, the authors studied the complicated buried karst and deep underground confined water, clarified the formation conditions of karst and underground confined water beneath a dam foundation, and divided the underground water system into two parts: the first one is an underground water system in cracks or karst; the other is underground confined water system. Then it is pointed out that there is no hydraulic relation between the two systems. These results will be beneficial to selection of dam sites and engineering construction.
ased on the field investigations and from results of chemical experiments, the authors studied the complicated buried karst and deep underground confined water, clarified the formation conditions of karst and underground confined water beneath a dam foundation, and divided the underground water system into two parts: the first one is an underground water system in cracks or karst; the other is underground confined water system. Then it is pointed out that there is no hydraulic relation between the two systems. These results will be beneficial to selection of dam sites and engineering construction.
1998, 6(2): 181-185.
or study of landslide, a thermodynamic model for mass flow at finite deformation is suggested in the paper. It allows the mass to move under the effect of non incompressible and the unperfect gas flow. The important restrictions on different spaces of four characteristic parameter in this model and the difference between the relevant models are discussed in this paper.
or study of landslide, a thermodynamic model for mass flow at finite deformation is suggested in the paper. It allows the mass to move under the effect of non incompressible and the unperfect gas flow. The important restrictions on different spaces of four characteristic parameter in this model and the difference between the relevant models are discussed in this paper.
1998, 6(2): 186-192.
ow there are various methods for soft soil soundation srocessing, each of them has its advantages and disadvantages. If one method is used properly, it is safe, fast, and economic; otherwise, it may cause inestimable lose. Soft soil foundation processing for the airport projects is usually based on the engineering characteristics, construction site conditions, and building material resource for each main part of project. The purpose of this paper is to research the soft soil foundation processing of the Shenzhen Airport Project Phase 1 and to look ahead the soft soil foundation processing in the Shenzhen Airport Project Phase 2.
ow there are various methods for soft soil soundation srocessing, each of them has its advantages and disadvantages. If one method is used properly, it is safe, fast, and economic; otherwise, it may cause inestimable lose. Soft soil foundation processing for the airport projects is usually based on the engineering characteristics, construction site conditions, and building material resource for each main part of project. The purpose of this paper is to research the soft soil foundation processing of the Shenzhen Airport Project Phase 1 and to look ahead the soft soil foundation processing in the Shenzhen Airport Project Phase 2.