土钉支护结构极限支护深度的研究

土钉墙支护软弱地基基坑，只能适用于一定的开挖深度，即土钉基坑支护结构具有极限开挖深度。为此，提出了土钉支护结构极限开挖深度的确定方法，以淤泥类地层基坑作为研究对象，研究了土钉支护结构的极限开挖深度问题，以及研究了土钉墙墙面坡度、地面超载、土层物理力学性指标以及土钉直径等变化时对极限开挖深度的影响。对于位于淤泥类、淤泥质类土层中的基坑，其极限开挖深度可分别取为5.0 m和6.0 m。

Limit protection depth of soil nailing protection structures

Soil nailing wall which is developed to protect excavation in soft ground is applied to definite excavation depth. Soil nailing protection structure has the limit excavation depth, namely. The method of confirming the limit excavation depth of soil nailing protection structure is put forward; the limit excavation depth of soil nailing protection structure is studied based on the silt foundation. The influences of soil nailing wall slope, surcharge, physico-mechanical properties, and soil nailing diameter on limit excavation depth are studied. For the excavations in the silt and mucky soil grounds, the limit excavation depths are 5.0 m and 6.0 m respectively.