Study On The Technology Of Cable Construction For Anchor Against Pull-out In Existing Buildings In Metro Construction

In view of the increasing complexity of the subway station and the surrounding environment of the shield area,it will inevitably encounter the situation of the underground anchor cable during the construction process,which will seriously affect the normal construction of the subway.During the construction of the shield area,Through the pre-treatment is completed,otherwise the anchor will be wrapped in the cutter and screw machine,a serious cause of the cutter and screw machine stuck and can not function properly,the need for underground open processing,which undoubtedly increased the construction risk.Under the construction of the subway construction of anchor cable processing technology in Shanghai,Shenzhen,Guangzhou,Beijing subway construction in a more successful case,but in Zhengzhou is still a small number,so for Zhengzhou City Rail Transit Line 5 project 04 standard.It is necessary to carry out comprehensive research on a series of construction techniques such as cable treatment methods,and put forward general technical guidance.In the bolt safety design,single safety coefficient usually using the limit equilibrium method to evaluate its safety.However,the definite value analysis method in engineering design slightly reflect the existence of various uncertain factors.The reliability theory because it can give full consideration to the matter of uncertainty and attention in the civil engineering and water conservancy and other engineering fields.In this paper the design parameters of anchor as random variables,the safety evaluation of the application of reliability theory to anchor pullout resistance,tensile strength from the anchor rod,the three aspects of grout and the rod body adhesive strength and grout and soil to investigate the relationship between reliability index and the safety coefficient of anchor,and the differences between the three aspects of safety factor and reliability index.