盾构隧道侧穿公路桥桩影响分区与加固控制研究OA

To investigate the effects of shield tunneling on existing highways,numerical simulations were conducted to analyze the deformation of bridge pile foundations,establish zoning control criteria,and define the influence range of shield tunneling adjacent to highway bridge piles.A zoning discrimination formula based on bridge pile horizontal displacement was proposed to delineate the boundaries of large,medium,and small impact zones,and the effectiveness of corresponding reinforcement measures was evaluated.The method was validated using the interval tunnel between Xiaogaozhuang Station and Qingdao Road Station of Jinan Metro Line 4,where the shield tunnel passes adjacent to the bridge piles of the Beijing-Taiwan Expressway.The results show that for the large and medium impact zones,sleeve valve pipe grouting and grouting above the shield segments reduce the maximum horizontal displacement of bridge piles by 58.82%and 12.19%,respectively.Grouting reinforcement reduces bridge pile settlement induced by tunneling by up to 74%for the right-line excavation and 40%for the left-line excavation,while the differential settlement of the bridge deck is reduced by 1 mm.