| With the rapid development of China’s economy,the continuous promotion of planning and construction of large urban agglomerations such as the Yangtze River economic belt,Guangdong Hong Kong Macao Bay area and xiong’an new area,and the continuous increase of urban population,coupled with the increasingly prominent contradiction between land development and protection,there are more and more slope and foundation pit combined support projects in engineering construction.However,at home and abroad,the research results on the related topics of slope and foundation pit combined support are still limited.The current national and local design codes,industry standards,engineering guidelines and works of experts and scholars have not provided enough theoretical basis for the design of slope and foundation pit combined support structure.However,many practical engineering problems of slope and foundation pit combined support structure bring great trouble to the design and construction technicians,this subject needs to be paid attention to and solved.This paper summarizes the current research status of slope engineering,foundation pit engineering and slope and foundation pit combined support engineering at home and abroad,introduces the common deformation laws,instability types and their main reasons in foundation pit and slope engineering,summarizes the existing analysis methods of foundation pit and slope stability,and makes analysis on various methods proposed in the current specifications,works of experts and scholars and engineering manual A reasonable evaluation is given,and the practicability,advantages and disadvantages of various methods are pointed out.Combined with the current analysis methods of slope engineering and foundation pit engineering stability,according to the characteristics of the combined support structure of slope and foundation pit,the stability analysis method of the combined support structure is discussed.Based on the actual engineering project,the paper generalizes the elements,focuses on the analysis and research of the deformation,internal force change and stability change trend of the combined support structure under the conditions of different slope height,foundation pit depth,platform width,combined support form and geological conditions,and emphasizes the stability of the lower temporary foundation pit support structure of the combined support structure and the deformation of the upper permanent slope The influence of the stability of the combined support structure needs the overall comprehensive control of the stability and deformation according to the unified requirements of the permanent support structure.At last,the deformation and stability characteristics of the combined support structure are analyzed by combining numerical simulation and field measurement.The main research contents and achievements are as follows:(1)By consulting and studying a large number of relevant documents and materials of foundation pit and slope engineering at home and abroad,especially the design and construction practice and research results of the combined support of slope and foundation pit,this paper summarizes the relevant theories of foundation pit and slope engineering at present: Classic earth pressure theory,soil and water pressure theory,deformation mechanism of foundation pit and slope and stability analysis and calculation method Law.Through the study and summary of the existing theory,combined with the practical cases of relevant literature,the paper analyzes the stress,deformation and stability mechanism of the combined support structure of slope and foundation pit,and provides a new idea and design method for the combined support design of slope and foundation pit.(2)Based on the actual engineering case,and for the analysis model to carry on the element generalization processing,in order to be more close to the calculation analysis of the actual engineering design,the plane strain two-dimensional model is used to study the changes of the slope and the foundation pit joint support under the single influence factors such as the slope height,the foundation pit depth,the distance between the slope toe and the foundation pit top,the rock and soil quality conditions,the joint support form and so on This paper summarizes the influence law of the joint support structure of slope and foundation pit under various influence factors,verifies the design control method suitable for the joint support of slope and foundation pit,and puts forward the key points of design and construction for engineering practice.(3)Taking the engineering example of the slope and foundation pit combined support of the medical technology complex building of the second people’s Hospital of Yunnan county,Yunfu City,Guangdong Province as an example,the geotechnical geological characteristics of the project area are analyzed,the slope treatment scheme,the foundation pit support design scheme and the spatial relationship between the foundation pit and the slope are introduced in depth,and the 3D finite element software MIDAS GTS is used Nx carries on the numerical analysis and simulation to the project,through the comparison of the numerical simulation results and the actual monitoring data,verifies the rationality of the finite element analysis and the rationality of the joint support scheme of the slope and the foundation pit.(4)Combined with the characteristics and engineering characteristics of the slope and foundation pit combined support structure,this paper puts forward the precautions and preventive measures for the engineering investigation,design,construction and monitoring of the slope and foundation pit combined support structure,so as to provide safety guarantee for the slope and foundation pit combined support project. |
