Risk Assessment Of Geotechnical Investigation Quality Of Underground Station In Soft Soil Area

Since China’s entry into WTO,subway construction is in the ascendant.At present,the survey work is an important part of the construction of the project.The defects of the survey quality are related to the design and construction of the underground subway station,and even the success or failure of the project.In view of the imperfection of the research on the quality risk of engineering investigation project,this paper studies the quality risk management of investigation combined with the construction project of S18 underground station of subway line S1 in Suzhou soft soil area,and formulates countermeasures,which is very meaningful.Combined with the characteristics and project management system of underground station survey in soft soil area,this paper analyzes the internal and external quality risk factors of survey units that affect the survey quality in the whole survey work,and puts forward the comprehensive and systematic identification and induction of survey quality risk factors by using Delphi method,and obtains the sample data required for research and analysis.The results show that the expert survey method is an effective method to identify the quality risk of investigation because of its complex work flow,numerous internal and external participants and various risk sources.This paper adopts qualitative and quantitative evaluation methods.In the process of evaluation,the mathematical statistics method,which is often used in geotechnical engineering investigation,is introduced,including the concepts of average value,standard deviation,deviation and coefficient of variation δ 3,the maximum deviation D is less than three times of the standard deviation 3S,to test the consistency and reliability of the statistical sample data,to ensure the preciseness of scientific research.Through statistical calculation,the preliminary qualitative evaluation ranking of the importance of risk factors of survey quality is obtained;Then through the risk importance = risk probability × The influence degree calculation and evaluation method,quantitative evaluation of the importance of risk factors in the investigation order.By comparing the preliminary qualitative assessment and final quantitative assessment of the importance of risk factors of survey quality,it is concluded that the assessment and ranking of the importance of risk factors of survey quality are consistent with the actual situation of risk management of geotechnical engineering survey quality,It shows that the introduction of mathematical statistics method which is often used in geotechnical engineering investigation combined with qualitative and quantitative evaluation is an effective risk assessment method of investigation quality.Finally,the quality risk identification system and qualitative and quantitative evaluation model of underground station survey in soft soil area are applied to the survey project of S18 underground station of Suzhou Metro Line S1.Combined with the qualitative and quantitative evaluation model,the importance order of quality risk is obtained,and the Countermeasures of quality risk factors are formulated;In the survey project of S18 underground station of Suzhou Metro Line S1,no survey quality accident has occurred,and good survey quality risk management effect has been achieved,which also confirms that the research results of this subject have certain reference value for the actual survey work.Through the research of this subject,the importance order of risk factors of survey quality is made clear,and the corresponding measures are put forward.This paper only makes a preliminary study on the quality risk management of survey,hoping that the research and analysis methods and results of this paper can inspire similar engineering survey projects,and provide some reference for the quality risk management of survey units.