| According to the field investigation,based on the engineering geological conditions,combined with the GNSS displacement monitoring and In SAR displacement monitoring,this paper describes in detail the deformation and failure characteristics,deformation development and distribution rules of the three groups of deformation bodies of Xingguang.Based on the discrete element software 3DEC,the genetic mechanism of the three groups of deformation bodies of Xingguang is analyzed.Then,the finite difference software FLAC3 D is used to store the three groups of deformation bodies in the reservoir area The stability of the parts is analyzed.Finally,the harmfulness of the deformed body is analyzed.Finally,the following conclusions are obtained:(1)The deformation body of Xingguang three group is the protruding ridge between the taoerpo gully at the upstream and Hongyan gully at the downstream,which presents a state of three faces empty.The vertical distribution range is 420 m ? 1400 m in elevation,and above 1360 m is a gentle slope platform,with a slope of about 5°,between 1000 M ? 1360 m in elevation of 25°?30°,and below 1000 m to the riverside of 40°? 45°.The slope shape is relatively straight,and the slope is piled up in Quaternary system The deposit is thin.Through the field and adit survey,the bank slope of Xingguang group III has strong toppling deformation.The bank slope has been toppled from the original bedding structure slope to the reverse slope,and the attitude of the rock stratum has changed from N5°? 20°W/SW?65°? 85°to N0°?30°W/NE ?25°? 75°.According to the monitoring data and field survey,the deformation body of Xingguang group III is not the traditional deformation in the free direction,but inclined to the upstream According to the exposure of typical adit pd01 and pd03 on the deformation body,the horizontal burial depth of the bottom boundary of the strongly dumped rock mass is 252 m and 200 m respectively,and the total volume of the strongly dumped rock mass is about 2.15 × 108m3.(2)After water storage in the reservoir area,the deformation and destruction of the bank slope surface intensified,and the large-scale cracks increased from 5 to 13,and the accumulated displacement of the bank slope measuring points continued to increase.When the water level in the reservoir area rose or fell,the average deformation rate of each measuring point was significantly higher than the average deformation rate when the water level in the reservoir area was stable.According to the investigation and statistics of the deformation characteristics of the rock mass inside the adit,the internal rock mass changed It can be divided into three types: toppling and falling,toppling bending and toppling breaking.According to the statistics and analysis of the relevant deformation indexes,the bank slope deformation of Xingguang group III is divided into extremely strong tilting zone,strong tilting zone,weak tilting zone and normal bedrock.At the same time,combined with insra monitoring plane deformation division,the bank slope spatial structure mode of Xingguang group III deformation body is divided into three-dimensional three-dimensional.(3)The evolution process of the deformation body of Xingguang group III mainly goes through three stages: in the early stage of the dumping deformation,the rock stratum of bank slope is dominated by the shear dislocation deformation in the layer;in the middle stage of the dumping deformation,under the effect of in-situ stress,the soft rock is subject to plastic deformation,and the hard rock is subject to brittle deformation,showing the phenomenon of dumping breaking;in the late stage of the dumping deformation,with the dumping deformation As a result,the soft rock changes from plastic deformation to brittle deformation,and a series of intermittent fracture surfaces are produced in the rock mass of bank slope.(4)Based on FLAC3 D,when the water level of the reservoir rises from 540 M to 600 m,the stability coefficient of the bank slope decreases from 1.87 to 1.76,which does not develop into a concentrated zone of through shear stress increment,and the bank slope is generally in a stable state;under the long-term effect of the reservoir water,the displacement of the bank slope gradually converges to the extremely strong dumping area,and the shear strain increment shows a phenomenon of continuous backward expansion.When the calculation time is 25 years,it is extremely strong The displacement of the dumping area suddenly changes,and the maximum displacement increases from 169 cm to 1691 cm.When the calculation time is 30 years,the shear strain increment belt has been completely penetrated in the extremely strong dumping area.At this time,the stability coefficient of the bank slope decreases from 1.66 to 1.11.Based on the simulation results,it is preliminarily judged that there is the possibility of instability and damage in the extremely strong dumping area in the 25-30 years after August 20,2018,if the reservoir water rises and falls frequently,The process will also be advanced.(5)Based on the analysis of the risk of surging wave and river blocking after the instability of the extremely strong deformation area of the deformation body,the results are as follows: the height of the surging wave at the falling water of the landslide is 11.43 m,the height of the surging wave at the Xiluodu dam site is less than 1.4m,the height of the surging wave from the bank slope of Xingguang group III to the bank residential area is about 3.4m,and the impact of the surging wave on the hub buildings such as Daba is small,which may affect the bank residential area and its bank slope of Xingguang group III According to the empirical formula method,the minimum amount of earth and stone required by the unstable deformation body is about 1.28 × 108m3,and the total volume of extremely strong deformation area is about 5.31 × 107m3.Meanwhile,based on 3DEC river blocking simulation analysis,the dam crest height of earth and stone dam formed after the bank slope is unstable is about 100 m,so the possibility of river blocking is small. |
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