Analysis Of Composite Soil Nailing With Limited Equilibrium Method

The soil nailed support system for deep foundation pit supporting and slope stability has got more application for its advantages, such as easy to implement, safe and less investment. This technology for temporary and permanent structures is currently growing with increasing local experience, and many countries increasingly recognize its specific advantages, especially for stabilization of railroad and highway cut slopes. However, it is short of thorough and systematic research on this new technology. And some accidents have taken place when soil nailing was used for deep foundation pit supporting with soft soil layers. It should be emphasized that further experimental research about application of composite soil nailing support is necessary.The aim of this paper is to analyze composite soil nailing support with limited equilibrium method and to investigate the influence of retaining parameters on the stability of soil nailing structure.At first, a limited equilibrium method is proposed for the stability analysis of soil nailing. The effective of the shearing of soil nail is discussed. Secondly, novel ideal is applied to analyze composite soil nailing support. Parametric studies are carried out to investigate the influence of retaining parameters such as nail length, inclination, spacing, anchor inclination etc., on the stability of soil nailing structures.Some significant conclusions are remarked as follows:1) The shearing of soil nail has little influences on soil nailingstructures. Considering this, the effective of shearing of soil nail can be neglected.2) The retaining parameters of soil, anchor and stake have influences on the soil nailing structures. Fifteen degree or so of nail and anchor inclination is the optimized. Some certain value of nail space is proposed by which soil nailing structure and earth nail wall can be differentiated. The method to analyze the gravity retaining wall is applied to earth nail wall. Anchor and stake parameter should be considered to composite soil nailing structure applied to weakfoundation.