Micro-disturbed Construction Control Technology System Based On Subway Construction Process And Its Application

Due to the rapid development of subway,in the city it inevitable crossing underneath important and protection level built.In the face of the complicated surrounding environment and the ascending humane environment protection,the safety of subway construction and build is facing a severe test.If the subway construction control does not reach the designated position,which will lead to the large influence on surrounding environment.For instance,make the road crack and collapse,underground pipes burst,houses damaged,even endanger people's life safety,etc..So it is particularly important that establish micro-disturbed construction control technology system based on subway construction process.Both ensure the construction safety and built safety.But it has no mature and applicable method for micro-disturbed construction control.The research in the field is still in the exploration and development.This paper,combined with the project of No.2 and No.8extension line of Guangzhou subway(the 14 th section),has a research of micro-disturbed construction control technology based on subway crossing underneath complicated environment.Apply research results to ensure the safety of tunnel construction and ground surface structures,which guarantees metro operation.The main work of this paper includes the following parts:(1)Through the analysis of the mechanism of stratum deformation caused by the subway construction process and the interaction mechanism of the deformation stratum and built,this paper puts forward the micro-disturbed disturbance index.Through analyzing the mechanism of change of pore water pressure when the tunnel excavation,this paper puts forward the micro-disturbed pore water pressure change rate index.According to the related literature at home and abroad and the specification,this paper determine the permissible value of each micro disturbance control indicators.(2)With numerical analysis software FLAC3 D simulates the actual project to predict the degree of disturbance of subway construction,that predict whether micro disturbance control parameter values within the scope of permissible value,which to determine whether construction schemes and support form meet the micro disturbance construction requirements.Real-time monitoring the value ofmicro-disturbed index during the construction whether or not within the scope of permissible value,if not satisfied,then adjust the related construction parameters,thus achieve micro disturbance in the construction.Both in front of the construction control the construction disturbance,and in the construction control the construction disturbance,which formed micro-disturbed construction control technology system based on subway construction process.(3)Apply the micro-disturbed construction control technology system to solve the problem of micro-disturbed construction control of the shield crossing underneath overhang and mining tunnel close crossing underneath the existing rectangular pipe jacking tunnel.Respectively by means of displacement index and pore water pressure change rate index,the subway construction disturbance is controlled in micro-disturbed range.It shows that the system is feasible and effective.