考虑既有多层建筑物的盾构隧道施工诱发的地表变形预测

Ground deformation prediction induced by shield tunnelling considering existing multi-story buildings

准确预测建筑物下盾构隧道施工对地表的影响,可以减少隧道施工对建筑物的影响。在多层建筑物下的盾构隧道施工过程中,建筑物的刚度和荷载会影响地层的变形。本文探讨了上述两个因素的影响程度和机制。首先,基于在半无限空间推广的Mindlin解法,建立了一种多层建筑物带来的附加应力和刚度影响建筑物下盾构掘进引起地层变形的计算方法。然后,在分析地表沉降槽和地表水平位移曲线构成的基础上,根据修正Peck公式和O’Reilly和New的公式以及目前的经验公式和修改后的公式,对四种情况下盾构隧道引起的地表变形进行了比较和分析,即无建筑物、建筑物的荷载、考虑建筑物的刚度、同时考虑建筑物的荷载和刚度。结果表明,只考虑刚度时表面沉降的最大值最小,而只考虑荷载时表面沉降的最大值最大。在实际应用中,应同时考虑建筑物的刚度和荷载。

Accurately predicting the impact of shield tunnel construction under buildings on the ground surface can reduce the impact of construction on buildings.During the process of shield tunneling under multi-story buildings,the stiffness and load of the buildings affects the deformation of the formation.This study explored the degree and mechanism about influence of the above two factors.First,based on the Mindlin’s solution promoted in semi-infinite space,a method was developed for the calculation of ground deformation caused by shield tunneling under multi-story buildings,including the influence of additional stress and stiffness brought by the buildings.Second,based on the analysis of the composition of a surface settlement tank and a surface horizontal displacement curve,a modified Peck formula and the formula of O’Reilly and New were reviewed.Finally,according to the present empirical formula and a modified formula,the surface deformation caused by shield tunneling was compared and analyzed in four cases:without buildings,with load of buildings,with stiffness of buildings,and with load and stiffness of buildings.The results demonstrated that the maximum value of surface settlement was the smallest when only the stiffness was considered,and it was the largest when only the load was considered.In practical applications,the building stiffness and load should be considered simultaneously.