1995 Vol. 3, No. 2
1995, 3(2): 1-11.
The shiplock slope at left bank of Wuqiangxi Hydroelectric Power Station consists of the pre-Sinian Pt1(mainly phyllitic slate) and Pt2 (mainly sndstone and slate).Stability of the slope is very bad because it is cut by faults and its rockmass is fractured.In order to ensure the safety during excavation process in the slope,the authors made a monitoring design for excavation according to the engineering geomechanics and the system science,and achieved considerable.
The shiplock slope at left bank of Wuqiangxi Hydroelectric Power Station consists of the pre-Sinian Pt1(mainly phyllitic slate) and Pt2 (mainly sndstone and slate).Stability of the slope is very bad because it is cut by faults and its rockmass is fractured.In order to ensure the safety during excavation process in the slope,the authors made a monitoring design for excavation according to the engineering geomechanics and the system science,and achieved considerable.
1995, 3(2): 12-20.
This paper provides a reslut of macroscopic and microscopic study of a new type of expensive soil, the eluvial-colluvial clay on basalt, found in Central Nei Mongol.The formation environment of the eluvial-colluvial expensive soil abnormally developed in Central Nei Mongol is revealed and the formation mechanism of bed engineering properties is discussed from the composition, physical and chemical properties, and microstructure of the soil. Then an engineering evaluation of the expensive soil is made.The finding of this type of expensive soil in northern China leads to revise the knowledge on regulaities of formation and development of expensive soil in northern China.
This paper provides a reslut of macroscopic and microscopic study of a new type of expensive soil, the eluvial-colluvial clay on basalt, found in Central Nei Mongol.The formation environment of the eluvial-colluvial expensive soil abnormally developed in Central Nei Mongol is revealed and the formation mechanism of bed engineering properties is discussed from the composition, physical and chemical properties, and microstructure of the soil. Then an engineering evaluation of the expensive soil is made.The finding of this type of expensive soil in northern China leads to revise the knowledge on regulaities of formation and development of expensive soil in northern China.
1995, 3(2): 21-28.
The Sanshandao gold mine is situated on the seashore frontier of the Laizhou Bay in Sandong Province, the engineering geology and hydrogeology conditions of the mine area are more complex. For this reason, there exist some specific geoengineering problems for underground mining of the gold mine. In this paper the characteristics of stress field are studied by using analysis method of geomechanical structural lines, in situ stress measurement and experiment method of Kairser effect of acoustic emission, respectively. The results suggest that the current tectonic stress in the mine area is N40E or so, NE = 110 bar or so,NE : V : NW = 1 : 0. 9 : 0. 65. This provides basic mechanical parameters or the stability evaluation of the underground mining.
The Sanshandao gold mine is situated on the seashore frontier of the Laizhou Bay in Sandong Province, the engineering geology and hydrogeology conditions of the mine area are more complex. For this reason, there exist some specific geoengineering problems for underground mining of the gold mine. In this paper the characteristics of stress field are studied by using analysis method of geomechanical structural lines, in situ stress measurement and experiment method of Kairser effect of acoustic emission, respectively. The results suggest that the current tectonic stress in the mine area is N40E or so, NE = 110 bar or so,NE : V : NW = 1 : 0. 9 : 0. 65. This provides basic mechanical parameters or the stability evaluation of the underground mining.
1995, 3(2): 29-41.
The deforming-cracking mechanisms of strong pulling-apart in south-north direction, weak pulling-apart in east-west direction ,and anticlockwise rotation on the horizontal were been recognized after analysis of distribution of coal mined-out area, geopressure action on the roof, and rock body fracturing and deformation in last twenty yeas in this article. On the above analysis,the authors made a series of calculations and applied them to engineering design for controling the Lianzi Cliff dangerous rock body.
The deforming-cracking mechanisms of strong pulling-apart in south-north direction, weak pulling-apart in east-west direction ,and anticlockwise rotation on the horizontal were been recognized after analysis of distribution of coal mined-out area, geopressure action on the roof, and rock body fracturing and deformation in last twenty yeas in this article. On the above analysis,the authors made a series of calculations and applied them to engineering design for controling the Lianzi Cliff dangerous rock body.
1995, 3(2): 42-46.
According to the engineering geological conditions and for design requirement in Sanshandao gold mine,a new method for it of analysis of stability of rock pillar is suggested, since the design size of pillar now is not rational. An effective approach recourse is to raise the loading capacity of pillars is also suggested if the design size is unchanged. Relation between the depth and the length of rock pillar is discussed in detail.
According to the engineering geological conditions and for design requirement in Sanshandao gold mine,a new method for it of analysis of stability of rock pillar is suggested, since the design size of pillar now is not rational. An effective approach recourse is to raise the loading capacity of pillars is also suggested if the design size is unchanged. Relation between the depth and the length of rock pillar is discussed in detail.
1995, 3(2): 47-53.
The waviness is found commonly in surface morphology of joints. In this paper the behaviors of joint closure model, considering waviness , are analysed. The deformation mechanism and closure behaviors of this kind of joints are discussed. The effects of irregularity variance, amplitude and frequecy of waviness on closure behaviors of joints are studied. Finally the joint closure model,considering waviness, is compared with previous models which considered waviness as random irregularities of joint morphology.
The waviness is found commonly in surface morphology of joints. In this paper the behaviors of joint closure model, considering waviness , are analysed. The deformation mechanism and closure behaviors of this kind of joints are discussed. The effects of irregularity variance, amplitude and frequecy of waviness on closure behaviors of joints are studied. Finally the joint closure model,considering waviness, is compared with previous models which considered waviness as random irregularities of joint morphology.
1995, 3(2): 54-59.
The sliding surface in a slope is described by using enlongated elements with eight nodes on the basis of non-linear finite element analysis in this paper. The coordinate system for adjustable nodes in finite element gride is modified to from a new gride. Thus, using existing basic gride framework, a stability curve for possible sliding surface in slope , K=f () ,is found by multiple finite element analysis and the most dangerous sliding surface is determined. On this basis a series of stability analysis is made.
The sliding surface in a slope is described by using enlongated elements with eight nodes on the basis of non-linear finite element analysis in this paper. The coordinate system for adjustable nodes in finite element gride is modified to from a new gride. Thus, using existing basic gride framework, a stability curve for possible sliding surface in slope , K=f () ,is found by multiple finite element analysis and the most dangerous sliding surface is determined. On this basis a series of stability analysis is made.
1995, 3(2): 60-69.
Precipitation is one of main factors triggering generation and reactivation of landslides. Based on analysis of some typical landslides in Three Gorgearea of Yangtze River, the authors get several threshold values of precipitation and use them to assess the probability of the landslide occurence.
Precipitation is one of main factors triggering generation and reactivation of landslides. Based on analysis of some typical landslides in Three Gorgearea of Yangtze River, the authors get several threshold values of precipitation and use them to assess the probability of the landslide occurence.
1995, 3(2): 70-73.
It is found that it is not perfect to forectcast landslide only from the rate of landslide displacement. In this paper,the author suggests a new criterion for forecasting impending slide of accumulation landslide after analysis of dynamic characterisitic of displacement vector angle of Xintan landslide.
It is found that it is not perfect to forectcast landslide only from the rate of landslide displacement. In this paper,the author suggests a new criterion for forecasting impending slide of accumulation landslide after analysis of dynamic characterisitic of displacement vector angle of Xintan landslide.
1995, 3(2): 74-77.
Expansive soil found in the border area,Huichun,Northeast China,is mainly distributed in the marginal parts of three basins,Hunchun,Liangshui,and Qingrong basins as well as the second-third-order terraces of rivers. The expansive soil is underlying by shale, sandstone, and conglomerate of the Tertiary system. The found of expansive soil in Hunchun area indicates its wider distribution in China and its importance for the further theoretical and for capital construction in the border area.
Expansive soil found in the border area,Huichun,Northeast China,is mainly distributed in the marginal parts of three basins,Hunchun,Liangshui,and Qingrong basins as well as the second-third-order terraces of rivers. The expansive soil is underlying by shale, sandstone, and conglomerate of the Tertiary system. The found of expansive soil in Hunchun area indicates its wider distribution in China and its importance for the further theoretical and for capital construction in the border area.
1995, 3(2): 78-85.
Acrylamide is a kind of chemical material which was used for curtain-grouting in many hydroelectric projects. However the time-variant effect of the material has been studied rarely. Taken Chencun Water Power Station as an example, it is studied synthetically on the basis of the detailed monitoring data, investigation in situ, and analysis in Lab. It is pointed out that the effect of anti-seepage and uplift pressure reduced due to acrylamide curtain under dam sections 7 to 17 in generally good and steady state. However, its effect of anti-seepage seems to be weakened locally.The special attention should be paid to this abnormal phenomenon and if necessary, some observation and measures must be taken,so as to ascertain the normal operation of the project.
Acrylamide is a kind of chemical material which was used for curtain-grouting in many hydroelectric projects. However the time-variant effect of the material has been studied rarely. Taken Chencun Water Power Station as an example, it is studied synthetically on the basis of the detailed monitoring data, investigation in situ, and analysis in Lab. It is pointed out that the effect of anti-seepage and uplift pressure reduced due to acrylamide curtain under dam sections 7 to 17 in generally good and steady state. However, its effect of anti-seepage seems to be weakened locally.The special attention should be paid to this abnormal phenomenon and if necessary, some observation and measures must be taken,so as to ascertain the normal operation of the project.
1995, 3(2): 86-96.