平行隧道施工引起地表沉降的数值试验研究

Numerical Experiment Studies on Groud Settlement During the Parallel Tunnels Construction

浅埋暗挖隧道施工产生的地表沉降是施工过程中令人关注的问题,采用数值试验的方法,通过模拟假设、建立模型和数值计算,研究了相邻隧道断面不同布置方式和注浆材料参数对地表沉降的影响.结果表明:隧道埋深越深,越需要大的隧道间距来实现沉降槽的双峰状态.在隧道埋深为2倍洞径时,倾斜布置条件下双隧道的垂直距离和水平距离接近2.5倍洞径时产生的地面沉降较小,垂直布置条件下双隧道间距越大,产生的地面沉降越小.拱顶注浆对控制地表沉降有明显效果,注浆参数提高要比注浆层厚度增加的效果好.

Ground settlement is an issue of common concern in shallow-buried parallel tunnel construction, especially in urban metro section construction. This paper presents a parametric study to investigate the influence of some important factors on ground settlement using numerical experiment method. The results indicate that the bimodal soil settlement results from the large tunnel center space and deep tunnel buried depth. The smaller ground settlement is achieved when horizontal distance and vertical distance are both close to 2.5D in inclined alignment and the bigger tunnel space in vertical alignment with the 2D tunnel depth. Grouting is very effective to control arch crown settlement. Improving the gouting parameters is better than increasing the thickness of grouting layer to control the arch crown settlement.