Analysis Of Influence Of Shield Construction On Buildings Adjacent To The Frame Structure

Nowadays,the subway has become the most convenient and fast city transportation.Therefore,many big cities are actively constructing subways.Even some second-and third-tier cities have begun planning for the subway,which is more and more concerned about the safe construction of subways.Due to its safety,rapid construction and small disturbance to the stratum,the shield machine is widely used in subway construction.However,regardless of the advantages of the shield machine itself,due to the complexity of the rock and soil body and the instability during excavation,the shield construction will still cause some settlement on the upper building and the stratum.This requires strict control of the construction process to avoid excessive settlement and damage to the building,thus causing unnecessary losses.Therefore,it is necessary to study the settlement changes of the surface or surrounding buildings during the construction of the shield.Only when the settlement value is controlled within the required range can safety construction be ensured.This paper established a shield construction project in a section of Science Avenue Station to Qimen Road Station of Hefei Metro Line 4,and studied the influence of shield construction on the upper multistory frame structure houses.Firstly,based on the actual engineering situation,the MIDAS GTS finite element software was used to build the 3D model,and the 3D model calculation results were compared with the actual monitoring data to verify the accuracy and reliability of the model.Then the model was used to simulate the shield construction.The influence on the upper building was analyzed with the deformation process of the building as the shield construction process progresses.Then,the model of different building locations was established under the same conditions,and the influence difference was compared and analyzed.Through the analysis of the 3D model,the following conclusions are drawn:(1)Building settlement caused by the shield tunnel crossing the upper building.With the excavation construction,the distance of the shield machine from the building is gradually reduced,and the disturbance and influence it receives are greater.Moreover,the influence of the upper building on the stratum is different.When there is a building,additional stress will be generated on the stratum,which will increase the surface settlement.(2)By analyzing the maximum settlement of the building,the overall settlementdifference and the local settlement difference,it can be concluded that the basic lateral inclination rate is firstly increased as the tunnel excavation process increases,and the longitudinal section of the building is separated from the tunnel.The closer the slope is,the larger it will be.The basic longitudinal inclination rate gradually increases to a stable value as the tunneling of the shield tunnel increases gradually.(3)The influence of shield tunnel construction on the upper building has a certain relationship with the location of the building.There are some differences in the maximum local settlement difference between the building axis and the tunnel axis.The influence of the shield is increasing as the shield advances,and the closer to the tunnel,the impact It is also bigger.Moreover,when the shield is excavated through the building,the axis of the building parallel to the tunnel axis is greater than the maximum local settlement difference when the axis of the building is perpendicular to the axis of the tunnel.This is because the rigidity of the building is parallel when the axis of the building is parallel to the axis of the tunnel.It is larger than vertical,so the local settlement difference is also relatively small.