深基坑支护结构的实用计算方法及其应用

Practical calculation method of retaining structures for deep excavations and its application

对深基坑支护结构的受力和变形计算提出了一套系统的实用计算方法,较好地解决了基坑支护结构设计、计算的关键问题,并在广州地铁和许多重大基坑工程应用中取得了较好的效果。该方法把支护结构简化为一竖放的弹性地基梁,支撑、锚杆及岩土体用弹簧系统来代替,岩土的弹簧刚度可用岩土的变形模量来计算, 针对基坑工程施工和结构的动态特点,提出了一套系统的计算方法,其中包括考虑施工过程的增量计算法、合理确定支护结构入土深度的计算法、支撑加预应力及支撑拆除的计算方法等,并应用提出的增量法,首次较完整地对国际上著名的支护土压力 Terzaghi-Peck 表观土压力给出了理论解释,对岩土的变形模量提出采用承载力反算的经验方法,为岩土参数的确定提供了更简便的方法。这一系列的研究成果为深基坑支护结构的设计提供了一套新颖的实用计算方法,较好地解决了基坑支护结构中的一系列设计计算难题,已在工程实践中成功应用。

A systematic and practical method of calculation of internal forces and deformation of retaining structure for deep excavation is put forward; and by the method, the design of retaining structure for deep excavation can be perfectly finished. The method is applied to the deep excavation project of Guangzhou metro and other important projects; and it is proved to be effective and available .It simplifies the structure as an elastic beam on ground; and the braces, rock and soil are simplified as a spring system; the rock and soil springs can be express by the deformation modulus of the rock or soil. The systematic calculation method also includes the incremental calculation method that can be used to modeling the construction process, obtaining the embedding depth of the retaining structure reasonably; and it also can be used to modeling the preloading of the brace and the dismantling of the brace etc.. The famous Terzaghi-Peck apparent earth presure is firstly explained preferably by this method. The experiential calculated method for deformation modulus of soils by the bearing capacity is presented. The systematic calculation method provides an effect calculated method of retaining structure for deep excavation; and a series of key problems are solved preferably by the method. It is applied triumphantly in practice.