摘要
深圳大梅沙隧道修建于软弱围岩中,断面呈扁平状,且施工工序复杂,地层和支护结构的受力状态频繁变化。为保证施工过程中支护结构和围岩的稳定,采用ANSYS程序对施工过程中围岩和支护结构体的受力状态进行了模拟计算,结果表明:采用双侧壁导坑法施工,导坑的围岩应力呈不对称分布,尤其在临时支护与永久支护的结合部位会出现应力集中现象;中洞上步开挖是施工过程中最不利环节,容易产生较大的卸荷效应,引起拱顶和地表的大幅度沉降。据此提出了对拱部支护及时施作二次衬砌以及对拱腰和边墙底部围岩采取注浆加固等技术措施,保证了围岩和支护结构的稳定。
Dameisha tunnel,a lavae-span tunnel with a short-and-wide section,was located in rock masses.The stresses induced in the surrounding rock and supporting system were changed frequently with the complex working procedures.Therefore,it became important to ensure the stability of the rock and the construction.Stress conditions of the typical sections of the tunnel were then analyzed with ANSYS program.Result showed that the construction would be the worst stress condition and unloading effect occurred when the middle pit was excavated with both-side leading pit method being applied.Based upon the findings of the analysis,additional supporting to the arch supporting system and cementing to surrounding rock in the middle and foot of the tunnel was conducted and stability of the project was proved.
出处
《河北理工学院学报》
2004年第4期96-100,共5页
Journal of Hebei Institute of Technology
