地铁盾构隧道双线施工对地表沉降影响的预测及分析

Prediction and Analysis of the Impact of Double-line Construction on Surface Settlement of Subway Shield Tunnel

结合广州地铁12号线双线隧道工程,采用ABAQUS数值模拟方法,分析不同注浆层厚度、埋深比和隧道间距等因素对工程地质条件的影响,并提出相应施工控制措施。研究发现:注浆层厚度与地面沉降量成反比,0.3m为最佳注浆层厚度。地面侧向沉降量随埋深比的增大呈先增大后减小趋势,这与土的拱形作用有关。当2条并联巷道间距越大,左右巷道地面沉降越大;间距越小时,其相互作用越强,在共同受扰的范围内,沉降变形越大,沉降沟呈倒V形。当2条隧道间隔足够大时,2条隧道间的相互干涉作用被削弱,地面沉降变形被视为2条独立隧道沉降变形叠加,形成W形沉降沟。

Combined with the double-line subway tunnel project of Guangzhou Metro Line 12,ABAQUS numerical simulation method is used to analyze the influence of different grouting layer thickness,buried depth ratio and tunnel space on engineering geological conditions,and the corresponding construction control measures are put forward.It is found that the grouting layer thickness is inversely proportional to the amount of land subsidence,and 0.3m is the best grouting layer thickness.The lateral settlement of the ground increases first and then decreases with the increase of the depth ratio,which is closely related to the arching effect of the soil.When the distance between the two parallel roadways is larger,the ground settlement of the left and right roadways is larger.The smaller the distance between the two roadways is,the stronger the interaction is,in the range of common disturbance,the settlement deformation is larger,and the settlement ditch is inverted V-shaped.When the space between the two tunnels is large enough,the mutual interference between the two tunnels is weakened,and the ground settlement deformation is regarded as the superposition of the two independent tunnels settlement deformation,forming a W-shaped settlement ditch.