地震作用下邻近地裂缝带地铁隧道工程场地地表沉降研究

为了探讨地震和地裂缝耦合作用下位于地裂缝上盘的地铁隧道顶部地表沉降规律及其对附近建筑物的影响，以邻近穿越地裂缝场地的西安地铁3号线为工程背景，利用FLAC3D有限差分软件，结合理论分析，对西安人工地震波、El Centro波和Kobe波三种不同地震波作用下邻近地裂缝带地铁隧道建设场地地表沉降问题进行了研究。结果表明:地震作用下，隧道顶部一定范围内的地层沉降量显著大于其周围地层，形成宽度约9~16 m的沉降凹槽；El Centro波作用下沉降凹槽的宽度最大，约15.9 m，超越概率为10%的西安人工合成地震波次之，约11.6 m，而Kobe波作用下沉降凹槽的宽度最小，约9.5 m；隧道上覆地层沉降凹槽的沉降规律符合peck公式；隧道顶部约20 m范围内场地地表受地震和地裂缝耦合作用影响最强烈，沉降最大。 

STUDY ON GROUND SETTLEMENT OF ENGINEERING SITE OF METRO TUNNEL ADJACENT TO GROUND FISSURE ZONE UNDER THE ACTION OF EARTHQUAKE

In order to study the law of ground settlement at the top of subway tunnel located on the hanging wall of ground fissure under the coupling action of earthquake and ground fissure and its influence on nearby buildings, taking Xi''an Metro Line 3 adjacent to the ground fissure site as the engineering background, with FLAC3D finite difference software and theoretical analysis, the ground settlement of engineering site with a metro tunnel adjacent to ground fissure zone under the action of three different seismic waves, namely Xi''an artificial seismic wave, El Centro wave and Kobe wave, are studied. The results show that the settlement of strata at the top of subway tunnel with a certain range is significantly greater than that of the surrounding strata under the action of earthquake, and a settlement groove with a width of 9~16 m is formed. The width of the settlement groove under the action of El Centro wave is the largest, about 15.9 m, and the Xi''an artificial synthetic seismic wave that exceed the probability of 10% is the second, about 11.6 m; The width of the settlement groove under the action of the Kobe wave is the smallest, about 9.5 m. The settlement law of the settlement groove accord with the peck formula. The settlement of the site surface with a range of 20 m at the top of the metro tunnel is the largest as a result of the coupling action of earthquake and ground fissure.