四线临海隧道开挖渗流演变及参数影响分析

Analysis on seepage evolution and parameter influence of four-line seaside tunnel excavation

隧道开挖防水及渗水量控制是隧道施工和运营过程中的关键问题。为了更好地解决隧道渗水问题,依托青岛地铁昌乐路地铁站隧道开挖工程,结合渗流场基本理论,基于Abaqus有限元软件建立隧道开挖计算模型。按照施工顺序依次对初始渗流场、毛洞渗流场、注浆后渗流场及施做衬砌后渗流场4种工况进行模拟,分析渗流场的演变特征并计算其渗流量。同时对注浆圈厚度和注浆圈等效渗透系数2个参数对模拟计算结果的影响进行分析。研究结果表明:隧道开挖会使隧道周围孔隙水压力减小,两侧拱脚处渗流量最大,隧道帷幕注浆和施做防水衬砌对渗流场具有重要影响,可以有效减少渗流量。注浆圈厚度和等效渗透系数是影响渗流场与渗流量的2个重要参数,合理设置参数取值对隧道施工防水具有重要意义。

Tunnel excavation waterproofing and water seepage control are key issues in the process of tunnel construction and operation.In order to better solve the problem of tunnel seepage,this paper relied on Qingdao Metro Changle Road subway station tunnel excavation engineering,and combined with the basic theory of seepage field.The tunnel excavation model was established based on Abaqus finite element software.According to the construction sequence,the initial seepage field,the capillary seepage field,the seepage field after grouting and the seepage field after lining were simulated.The evolution characteristics of the seepage field were analyzed,and the seepage flow was calculated.The results show that tunnel excavation will reduce the pore water pressure around the tunnel,and the seepage flow at the arch feet on both sides is the largest.Tunnel curtain grouting and waterproof lining have an important impact on the seepage field,which can effectively reduce the seepage flow.The thickness of grouting circle and the equivalent permeability coefficient of grouting circle are two important parameters that affect the seepage field and seepage flow.Reasonable setting of parameter values is of great significance to the waterproof of tunnel construction.