盾构掘进期隧洞穿越竖井段对周围土体渗流场的影响研究OACSTPCD

In order to study the influence of tunnel crossing the shaft on the seepage field of surrounding soil during shield tunneling,the Chuanqin Tunnel in Henan Province is taken as an engineering basis,and a three-dimensional seepage finite element computational model of the soil around the shaft section during shield tunneling is established.The distributions and its evolution pattern of the seepage field of surrounding soil before and after crossing the ungrouted and grouted filled shaft sections are compared and analyzed.The results show that,(a)the maximum seepage gradient and unit discharge of the soil around the shaft increased by 6.00 and 4.29 times respectively compared with that before crossing the shaft,and the seepage surface of the soil around the shaft is gradually elevated and the isotropic line became more intensive;and(b)the maximum seepage gradient and unit discharge of the soil around the shaft decreased significantly after crossing the grouted and filled shaft.Crossing the shaft during tunneling would affect the seepage field of surrounding soil,reduce the stability of soil,and easily lead to seepage damage.Meanwhile,grouting to fill the shaft can effectively reduce the impact of tunnel excavation on surrounding soil and improve the stability of soil.