双排挤扩支护桩试验研究

介绍了一种新型基坑支护桩——双排挤扩桩，探讨了双排挤扩支护桩的挤密效应、受力机制、工作特性和计算方法。土工模型试验和数值模拟试验表明，双排挤扩支护桩受力体系近似于一种特殊类型的多层框架结构。与双排悬臂支护直桩相比较，双排挤扩支护桩的空间刚度大幅度增加，结构受力合理，桩顶位移减小，桩体弯矩正负交替分布，弯矩最大值减小，嵌固深度减小，支护高度增加，桩体材料得到全面利用。双排挤扩支护桩有着明显的技术优势，可降低风险，为深基坑工程提供了一种更加合理的新型支护手段。

Experimental research on squeezed pan piles in double-row as retaining and protecting of foundation excavation

A new type of retaining and protecting structure called squeezed pan pile in double-row is introduced; and then its compaction efficiency, loading transfer behaviors, characteristics and the calculation method are discussed. Squeezed pan piles in double-row are indicated that its stress system is similar to a special frame structure through model test and numerical simulation. Compared with the cantilever reinforced concrete retaining straight piles, the major characteristics of squeezed pan piles in double-row contain: (1) The space rigid is increased enormously; the displacement in top of piles can be reduced greatly. (2) The stress system is proper; bending moments are alternating distributed; the maximum bending moment is decreased. and (3) The embedded depth can be shortened; retaining height can be enhanced; the material of piles can be utilized sufficiently. It is concluded that the squeezed pan piles in double-row have many significant advantages including advanced technology and little risk. It will provide a more reliable method of retaining and protecting for foundation excavation.