【摘要】 在盾构隧道施工中,易因地层损失引起地面沉降。在PECK公式中,假定地表沉降槽面积等于地层损失,忽略了土体在开挖前后应力状态的变化而产生的变形,从而产生误差;在隧道拱顶,因土体的不均匀沉降形成土拱,部分土体自重应力被转移到邻近的土体而出现应力释放,引起土体回弹,因此土体沉降槽面积小于地层损失。基于此,本文提出了一种考虑隧道拱顶土体卸荷回弹后的沉降槽面积计算方法,并据此对PECK公式的地表沉降计算方法进行了修正。更多还原

【Abstract】 In shield tunnel construction, ground subsidence is caused by stratum loss. In PECK’s formula, it is assumed that the area of the surface subsidence tank is equal to the formation loss, and the deformation caused by the change of stress state of the soil body before and after excavation is ignored, thus causing errors. In the tunnel arch, the soil arch was formed due to the uneven settlement of the soil mass, and the stress release occurred when the dead weight stress of part of the soil mass was transferred to the adjacent soil mass, which caused the soil mass to rebound. Therefore, the area of the soil mass settlement tank was smaller than the ground loss. Based on this point of view, a new calculation method about settlement trough area was proposed considering unloading rebound for tunnel vault soil, and the PECK formula was modified.更多还原