| With the development of infrastructure in our country, the growing highway, subway and municipal construction in southern Karst region are facing the main geological problem, the karst problem. Therefore, a high precise and accurate investgation techonolgy of karst cave is badly needed in the highway, subway and municipal construction. The detection results can guide the karst disaster treatment of highway and subway.The soluble and karstification are various in the Shenzhen NO3 subway engineering, and the hydrogeology condition is complex and underlying karst cave has a large effect on the stability of elevated bridge piles. Research on karst development features and its project influence has been done, and the advanced investgation method and disaster treatment techonolgy which is applicable of different karst cave has been raised. Not only may it be the guidance of production practice, but also enrich the knowledge of bridge piles location and land collapse's treatment in karst region.This paper is based on field geological investgation and detailed analysis, combined with series of engineering geophysics such as high resolution resistivity method, the electrical profiling, very low frequency electromagnetic vlf-em method, shallow seismic method, GPR method, electromagnetic wave perspective and geophysical well logging, and maneuvering drilling, pumping test, groundwater monitoring and karst connected test to find out the location and scale of underlying karst cave in soluble section of Shenzhen NO3 subway.Secondly, calculation model of cave instability has been generalized based on the instability mechanism of underlying cave. According to the model, the loading of cave roof has been calculated. And by means of checking computation of anti-shear characteristics, checking shear and bending capacity, analysis on cave roof stability has been done.Finally, the disaster treatment plan has been raised based on the stability evaluation results of different cave type.
|
PDF Full Text Request