一种新型框架组合支挡结构的设计研究

铁路通过不具备暗挖条件的深厚土层地区,通常采用浅埋隧道方案。当放坡开挖受限制时,基坑支护和支挡结构成为工程设计的难点。基于《欧洲岩土设计规范》土压力的规定,笔者对新型框架组合支挡结构进行探讨,重点分析了理论计算模型、荷载、配筋等关键技术问题,完善了细节设计。研究表明:该结构既可解决基坑支护问题,又可作为铁路两侧支挡结构,并广泛适用于地下水丰富,放坡受限,且开挖深度较深的地区。该框架组合支挡结构整体刚度大,抗弯刚度、抗剪强度高,可有效降低悬臂高度和顶部位移。最后,结合某工程实例,说明了该新型框架组合支挡结构的适用性和应用前景,具有进一步推广的价值。

Design Research of the New type Frame Assembly Retaining Structure

While the railways go through the deep soil where the underground excavation can’t be applied, the shallow buried tunnel is usually adopted. When the slope excavation is restricted, excavation and retaining structures become the difficult of engineering design. Based on the specifications of soil pressure by the 《Eurocode 7: Geotechnical design》, the author discussed the new type frame retaining structure, especially analyzed critical technical problems such as theoretical calculation model、load、reinforcement. Etc., and the details of the design are perfected. Research shows that this structure solves the problem of the foundation pit supports and works as the frame retaining structure of the railway, which is widely used in the site with rich groundwater, where slope excavation is limited and excavation depth is deep. The overall stiffness of this structure is great with high flexural rigidity and shear strength which can effectively reduce the height of the cantilever and the top displacement of the structure. At last, the applicability and application prospect of the new type frame assembly retaining structure are explained with a project example, worth being further popularized .