土钉支护中土钉力和位移的计算问题

土钉支护是一种比较经济的支护方式，工程实践中已广泛应用，但其设计理论则相对缺乏。针对目前土钉支护设计中存在的主要问题，即土钉力和土钉支护位移的计算分析，以工程实测资料为背景，根据侧壁主动土压力与总土钉力相等的原则，考虑施工过程的影响和增量法的思想，提出了基于经验和理论相结合的土钉力计算公式。按照弹性力学理论，对由于土的开挖引起支护的土体侧移提出了简易的位移计算公式。通过工程实测检验了公式的正确性。这些计算公式简便，其结果较符合实际，较好地解决了土钉支护设计的主要问题，可为工程设计提供参考。

Calculation of soil nail forces and displacement in soil nailing retaining wall

Soil nailing wall is a more economical way of retaining and protection and has been widely used in engineering practice;but the design theory is still relatively deficient.This paper analyzes the main problems in the design of soil nailing retaining wall,namely,soil nail forces and displacement calculation;based on practical engineering experiments and considering the affect of the construction process with the incremental method,supposing that the active earth pressure acted on the retaining wall are equal to the sum of the soil nail forces,a simple method for calculating soil nail forces is proposed.Basing on the elastic theory,the formula for calculating the displacement of the soil nailing wall under excavation is put forward.The rationality of the method and formula is checked by engineering case studies.