Engineering Risk Analysis And Countermeasures Application Of Inner Bracing + Row Piles Composite Foundation Pit Supporting Structure

Deep foundation pit engineer is an important part of modern geotechnical engineering research,and its safety is an urgent problem to be solved in engineering.Along with the rapid development of our country's economy,the evasion of engineering construction has continued to expand,deep foundation pit engineering has undergone significant changes.On the one hand,more and more openers attach importance to the development and utilization of underground space,and the excavation depth of deep foundation pit continues to expand,which makes the support safety of deep foundation pit engineering face new challenges.On the other hand,the implementation of deep foundation pit excavation technology is difficult,especially in major projects,deep foundation pit risk accidents occur frequently,causing significant losses.The supporting structure of inner support and row pile composite foundation pit is the key work in deep foundation pit engineering.It not only sets high requirements for the technical level of the construction team,but also is easily influenced by the internal and external risk factors,which implicates quite harmful engineering risks and has a decisive influence on the implementation effect of deep foundation pit engineering.Ringing.If there is no scientific project risk management,it will lead to the increase of project cost and huge losses to the construction unit.Therefore,it is very urgent to analyze the engineering risk of internal support and row piles composite foundation pit supporting structure systematically and find feasible countermeasures.On the basis of previous studies,this paper takes the deep foundation pit project of Zhongwu Research Institute in Tianhe District of Guangzhou City as an example,and discusses the engineering risks of the composite foundation pit supporting structure with internal support and row piles from four aspects: risk identification,risk analysis,risk response and risk monitoring.Firstly,based on the existing literature,the related concepts of risk,risk management of deep foundation pit and supporting structure of composite foundation pit with inner support and row piles are summarized;secondly,the countermeasures and application of risk in deep foundation pit engineering are summarized,and the risk management process,management organization,management planning and deep foundation pit engineering are defined.The main points of project risk identification,risk analysis,risk response and risk monitoring.Thirdly,through the WBS work breakdown structure method,the risk of internal support + row piles composite foundation pit supporting structure is identified,and found that personal injury risk,economic injury risk and liability injury risk are three common risk types.Finally,taking the project of China-UzbekistanResearch Institute as an example,the paper discusses the three risks by using the method of risk possibility analysis.The pile rows of underwater C30 supporting piles(diameter 1200)+two C30 reinforced concrete inner support,the pile rows of underwater C30 supporting piles(diameter 1200)in the South and east of the foundation pit and the pile rows of underwater C30 supporting piles(diameter 1200)in the north and east of the foundation pit.Supported by three high-strength prestressed anchor cables,two high-strength prestressed anchor cables and C30 piles(diameter 800)under water on the west side of foundation pit,C30 cantilever supporting piles(diameter 800)under water on the north side of permanent slope and C30 cantilever supporting piles(diameter 1200)under water on the south side of temporary slope.Five supporting operations are carried out to analyze the personal injury risk,economic injury risk and liability injury risk in the inner support + row piles composite foundation pit supporting engineering.To this end,put forward feasible optimization suggestions,trying to innovate a set of risk analysis,risk management,insurance protection control as a whole,can effectively avoid the internal support + row piles composite foundation pit supporting structure risk analysis and control model.