岩溶地区端承桩复合桩基的工程实践  

Engineering Practice on End-bearing Composite Pile Foundation in Karst Area

作　　者：周峰[1] 屈伟[1] 陈杰[1] 

机构地区：[1]南京工业大学交通学院,南京210009

出　　处：《地下空间与工程学报》2016年第2期489-495,共7页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金青年基金(51008159);国家自然科学基金面上项目(51278244)

摘　　要：岩溶地区高层建筑基础若采用常规桩基,需进行一桩一探的施工勘探,不仅造价高工期长,而且成桩质量难以保证。本文介绍某工程天然地基虽具有较高的承载力,但仍无法满足高层建筑基础沉降量与软弱下卧层承载力的要求。本文提出端承桩复合桩基的方法,通过在桩顶设置变形调节装置,协调桩、土变形差,实现端承型桩的桩土共同作用,使天然地基承担大部分的上部结构荷载,不足部分由引入的少量桩基来承担。本文详细介绍了端承桩复合桩基的设计方法,并采用数值计算的方法对不同组别的复合桩基深入分析,结果显示,若刚度按实际计算值控制,端承桩复合桩基各项测试指标与设计值较为吻合,该工程目前已进入上部结构施工阶段。本工程采用端承桩复合桩基的设计方法可取得显著的经济效益,本案例可供同类工程借鉴。If the general pile foundation is used as high building foundation in Karst area,it needs construction exploration for each pile. Not only it has high cost and long construction period but also it is difficult to guarantee the piling quality. Although the natural foundation of the project had a high bearing capacity,it was still unable to meet the requirements of foundation settlement and bearing capacity of soft substratum. In this project we put forward the method of end-bearing composite pile foundation. We set settlement adjustor at the top of each pile to coordinate the deformation difference between pile and soil and implement the pile-soil combined action. So that the natural foundation carried most of the loads from upper structure and the rest was burdened by a small number of piles under the raft. In this paper we introduced the design method of end-bearing composite pile foundation in detail and made contrastive analysis of different groups of composite pile foundation through numerical calculation method. The result shows that if we control the value of stiffness according to the actual calculation,all the test targets meet the design value. This project adopting the end-bearing composite pile foundation can obtain remarkable economic benefit and it can be referred in the similar projects.

关 键 词：岩溶地区 变形调节装置 数值分析 复合桩基 桩土共同作用 

分 类 号：TU473.1[建筑科学—结构工程]