Study On Safe Influence Of Metro Tunneling Using Mining Method On Adjacent Building

In process of construction of urban rail transit network system,it is inevitable that the structures will cross through the downtown district of the city in an extreme short distance for many times.While in such district there have been many high-rise buildings as well as many buildings which are old with low structural strength and low ability to resist construction disturbance,metro construction activities will threaten the safety of the buildings inevitably. In order to minimize the influence to maximum extent,Mining method was applied widely in metro constructions.So it is necessary to study on the safety problem to the building influenced by the metro built by mining method.Influence predicting theory and Mining method were research on the background of construction of Beijing Metro line No.10 in this dissertation.The tunnel-soil-structure interaction research thought was present,and model built by MIDAS-GTS FEM software and simulations were detailed stated.Then theoretical research results were compared with real monitoring data to testify the feasibility of the predicting theory and method.Based on the theory and method,general rule of cross construction was researched in order to understand the additional strain of buildings and the interactive relationship among building,ground surface and tunnel in different operating mode.And then some methods and suggestions were presented to help defining the admissible settlement control criterion for old buildings,and safety evaluation methods and measures for cross construction were analyzed.According to building damage grading,statistical method and back deduction method were used to establish building admissible settlement standard.And then the two kinds of methods are used to case study to be testified to be feasible.Building adjacent grade and evaluation grade were classified and four-graded safety evaluation method for metro construction crossing building in an extreme short distance by Mining method was presented.Detailed safety evaluation flow was presented for buildings which were judged to be extreme adjacent or very adjacent,and then four-graded safety influence gradation was presented and applied into instances in this dissertation.Usual strengthening and protecting measures were divided into three types,and six principles should be presented,and finally isolation pile method was compared with pouring concrete method.