Study On Deformation Effect Of Multi Tunnel Parallel Side Crossing Adjacent Buildings

In a regional section of Beijing Rail Transit Line 8,the double track pipe gallery and double track tunnel are built in parallel.There are many buildings along the line,with poor geological conditions and high construction risk.In addition,the excavation of utility tunnel and subway tunnel will disturb many adjacent buildings,resulting in the overall settlement,uneven settlement and deformation of buildings.Based on the project,through the field monitoring and three-dimensional numerical simulation,this paper studies and discusses the influence of multi tunnel parallel side crossing construction on the settlement and horizontal displacement of surrounding buildings,and puts forward the corresponding control measures for the settlement and deformation of buildings.The main research contents and conclusions are as follows:(1)The settlement of buildings passing through foreign language bookstore project on the pipe gallery and tunnel side decreases or even slightly rises with the excavation side away from the excavation side.The settlement and inclination rate of the buildings are within the control standard of building deformation;the foreign language bookstore inclines towards the side adjacent to the excavation in the direction of the cross section of excavation,and inclines in the direction of the vertical direction to the south,and the overall slope is southeast.The horizontal displacement of the buildings in the pipeline gallery and tunnel side through foreign language bookstore project is different in the longitudinal direction of excavation,and the horizontal displacement of the foreign language bookstore is basically the same in the direction of the cross section of excavation.(2)Compared with no building crossing construction,the range of ground settlement caused by the crossing engineering with surrounding buildings is wider,and it mainly expands to the soil under the building foundation,and the surface and building settlement is larger;in the horizontal direction,the existence of buildings can restrict the soil displacement,but the corresponding range of soil displacement caused by excavation disturbance will increase.(3)When passing through adjacent buildings or complex strata,the reinforcement method of deep hole grouting can effectively improve the overall settlement,uneven settlement and inclination of buildings.The smaller the distance between the crossing project and the building,the more significant the disturbance of the excavation construction to the adjacent buildings;in the multi line crossing project,the vertical displacement and horizontal displacement of the surface and the building will increase in varying degrees with the different distance between the new crossing project and the building.The results show that the construction method of tunnel after pipe gallery has better effect on controlling the vertical displacement,horizontal displacement and inclination of buildings than the construction method of tunnel before pipe gallery and synchronous excavation of pipe gallery tunnel.