Shield Tunnel Experimental Study On The Influence Of Adjacent Continuous Concrete Wall

The subway has become one of the indispensable factors in urban traffic rapiddevelopment. With its unique advantages,the shield has become the most commonlyused method of subway construction. Shield excavation often inevitably affect adjacentcontinuous concrete wall,and cause the continuous concrete wall and surrounding soilsgenerate additional deformation and additional internal force, even endanger the safetyof the upper structure, so the research of shield advance influence on adjacentcontinuous concrete wall, to ensure the safety of adjacent foundations and shieldsmoothly excavation is of great significance. At present, many experts and scholars athome and abroad close to little study on the influence of the foundation construction,sothis topic research becomes increasingly urgent.By combining the indoor model test and calculation method of the finite elementsoftware ABAQUS,this paper comprehensively analysis the indoor model test of eightkinds of conditions, and uses the single factor analysis method to study the differentfactors,such as excavation depth, the tunnel axis and the level of undergroundcontinuous wall edge distance, tunnel buried depth, thrust, grouting pressure,and finallysummarized the shield advancing influence on adjacent continuous concrete wallconstruction and effective measures are put forward to eliminate or reduce the adverseeffect.The conclusions are as follows:1、The results of free field test show the application of the model for this paper isfeasible.The different working contions of indoor model test conclused the settlementlaw of adjacent soil and the soil pressure variation law of different soil layer are almostsame,but the main difference is the numerical difference,and the surface displacement atthe continuous concrete wall is obviously smaller than the other side;the closer withtunnel, the earth pressure of soil changes more intense. The adjacent continuousconcrete wall is basic in a state of tension caused by the soil stress release,but themaximum strain under different working condition is different in the position of the wallbody.2、Through the single factor analysis，the settlement of adjacent soil and the strainof the wall body are decreases as the horizontal distance between the tunnel axis and thecontinuous concrete wall increase within a certain range. But the tunnel buried depth ismore shallow,the settlement of adjacent soil is greater,so the tunnel buried deep should not be too shallow in the practical engineering.3、The results of the finite element method show the settlement of adjacent soil issmaller when the soil pressure in pressure cabin is the same as the original soilpressure.The strain of the wall body changes almost the same under the action ofdifferent grouting pressure,and with the grouting pressure becomes greater,the strain ofthe wall body changes bigger,but the location of the maximum strain appeared in thewall body stays the same.