桩锚与土钉水平向联合支护体系的土拱效应研究

The Soil Arching Action of the Combined Supporting Structure System Comprising of Pile Anchor and Soil Nail in the Horizontal Direction

土拱是支护体系开挖过程中形成的一种最自然和合理的传力形式,可改变土压力传力路线并引起支护结构内力重分布,是支护结构设计和施工中必然涉及和必须考虑的影响因素,但其形成机制及成拱条件,以及其对支护结构土压力分布特征的影响方面的研究还非常罕见.桩锚与土钉分属不同形式和性质的支护结构,将其作为联合支护结构进行设计时,开挖过程中必然存在内力重分布和变形协调的问题,针对该类支护结构的承载机理和变形特点,根据土拱性质,研究了联合支护结构中土拱的形成条件和拱形特点,对研究基坑支护结构的土拱效应提供了一定的理论基础.

Soil arch developed in the excavated procedure of the supporting structure system is one of the most natural and reasonable force transmission forms which may change the transmission line of the earth pressure and cause the redistribution of internal force in the supporting structure. When designing and constructing such support structures,the soil arching action must be taken into account as one of the most influential factors. However,relevant studies on the formation mechanism,the forming condition of soil arch and the distribution trait of the supporting structure are still very rare. Since the property of the poil anchor and the soil nail is absolutely different,the redistribution of internal force and deformation compatibility must exist in the excavated process of the supporting structure of poil anchors and soil nails. In this paper,concerning about the bearing mechanism and deforming characteristics,on the basis of soil arching properties,both the formation condition and the characteristics of the soil arch in the combined supporting structure are studied. As a result,the theory of the soil arching action in the foundation supporting structure would be provided.