Study On Risk Assessment Technology And Application Of Xiang'an Sub-Sea Tunnel In Xiamen

Conparing with general tunnel, subsea tunnel's investment is larger, and greater risk during construction. Once the risk event occurs, the consequences would be disastrous. Therefore, it is necessary to strictly control the construction risk.In the design phase, due to the limited geological information on risk assessment and control of construction can not meet risk control requirements. And to the construction stage, with detailed description of the geological information, risk control to meet the requirements of it. These thesis of tunnel engineering background, during the construction phase, through theoretical analysis, field research, test technology and other means to make a suitable risk assessment of tunnel construction methods.Thesis include the following components:methods research of risk assessment of tunnel construction, conventional methods of risk assessment theory, the design phase of risk assessment, the risk of sub-construction phase of field testing technology assessment and assessment.The research object is XiaMen sunsea tunnel in this paper.In the design phase, with the risk assessment method which Ministry of Railways recommend, assessing the construction risk of the tunnel. During the construction phase, firstly, establishing a suitable risk assessment index system. And then through collection of geological sketch of the construction phase, geological prediction and other information, classing the surrounding rock and groundwater. Secondly, by the fuzzy mathematics and statistical methods, investigations by experts rate,every single risk factors that affect the construction risk were calculated. Finally,construction risk of section of tunnel is assessed by AHP. After assessment,compare and contrast section under sea area with under land area in subsea tunnel.Finally, With theoretical background of statistical and fuzzy mathematics, mathematical relationship is established between monitoring data and probability of construction risk during construction.Later probability of risk of accidents is caculated. Selecting three-lane tunnel is excavated by CRD method for assessing object,and analysising the different levels of risk under different displacement size.