Research On Deformation Mechanism And Prediction Evaluation Of Owner's Camp Of A Hydropower Station

The hydropower plant owner's camp is located in the Lao People's Democratic Republic and is located in Funchary Province in northern Laos.Since the hydropower plant was built in 2013,it has been operating normally.In 2016,the dormitory building was partially cracked,and the surface between the camp and the office building also appeared Cracking and sinking.During the rainy season in 2017,the original cracks continued to develop,and the upper and lower retaining walls of the dormitory building were deformed and cracked.So far,cracks have begun to appear on the walls of office buildings and the retaining walls of basketball courts,and the cracking deformation is still continuing.In the rainy season,the slope often shows local cracking and deformation.If high attention is not paid,the slope camps will be affected.Safety poses a serious threat.In order to ascertain the cause of cracking in the camp and investigate the stability and deformation trend of the slope body,the paper carried out a study on the deformation mechanism and prediction evaluation of the owner's camp of the hydropower station.This paper analyzes the geological structure and deformation characteristics of the camp slope through on-site geological survey,on-site monitoring data and UAV aerial photography;the slope deformation is calculated through the calculation of camp building foundation settlement combined with FLAC^3D numerical simulation software,and the camp is comprehensively analyzed The reason and mechanism of slope deformation;using the limit equilibrium method and Geo Studio,FLAC^3Dnumerical simulation software to study the slope stability of the slope under different working conditions;fitting the relationship between the time variable and the displacement value,using the neural network model to The deformation trend of the camp slope in the next half year was predicted.The main achievements and understanding are as follows:?1?The geological structure of the study area is as follows:the campsite area is covered with thick residual slope accumulation,which is silt,silty clay and silty clay containing gravel;the residual slope accumulation in the campsite area is fully weathered The layer is made of weathered metamorphic sandstone,and the full weathering is sandy.The spatial distribution is relatively uniform and the thickness is large.The sand plate rock underlies the full weathering layer,and the base cover interface is chair-shaped,and the front edge is empty.?2?Based on the observations of camp building and site deformation phenomena and monitoring points,the basketball court and office building on the North East?NE?side have both settlement and slippage deformation.Slip deformation and large uneven settlement caused many large deformation failures with obvious cracking?which is basically consistent with the deformation trend and magnitude of the northeast area?.There is only a small settlement deformation in other areas?3?Calculate the settlement caused by the foundation bearing capacity of the camp building by the layered sum method and the standard method and compare it with the monitoring data,so as to accurately judge and analyze that the small settlement on the left side of the camp is artificially underfilled Due to the differential settlement caused by uneven thickness,the large amount of settlement deformation on the right side of the camp is caused by the component of slip deformation.?4?The FLAC^3D numerical calculation software was used to simulate the deformation of the camp slope under three working conditions,and the deformation process of the camp slope was grasped by numerical calculation;the slope displacement distribution map and the displacement map of each monitoring point of the camp were used to help determine the camp slope.Determine the scale and cause of the slope deformation.?5?Comprehensive analysis of the camp slope deformation mechanism:ground and building deformation are due to the combined effect of foundation soil bearing capacity and shear strength,precipitation-induced ground settlement?differential settlement?and deep shear creep,And the latter is dominant.Foundation settlement is caused by vertical compression deformation and consolidation of foundation soil under the action of additional stress.The horizontal displacement is the result of the shear creep of the slope of the accumulation body along the interface of the foundation under the load of the building and gravity.It is mainly induced by rainfall,and there will be a small amount of vertical deformation at the same time.At present,it can be judged that it is a"thick layer of soil slope"deformation body,and its potential landslide deformation mode is creep-slip-cracking type,and the mechanical action mode is push type.?6?The limit equilibrium method and Geo Studio,FLAC^3D numerical simulation software were used to study the failure mode of the ground deformation of the slope under natural,heavy rain,and earthquake conditions:the landslide is stable under natural conditions;Stable-basically stable;under seismic conditions are understable-basically stable,and the shear strain increment chart shows that the three conditions are not connected,and the stability is better.?7?Using the BP neural network model,with 26 data as training samples,the deformation trend in the next six months is predicted.The overall deformation of the slope is in a larger trend,but the deformation trend is slower and will reach stability in a certain period of time.