静钻根植排水桩技术及模型试验研究  

Novel technology of statical-drill and rooted drainage pile and its large-scale model test

作　　者：邓岳保[1] 张日红 孙嘉烽 陈紫强 陈克伟 严天龙 DENG Yuebao;ZHANG Rihong;SUN Jiafeng;CHEN Ziqiang;CHEN Kewei;YAN Tianlong(College of Civil and Environmental Engineering,Ningbo University,Ningbo 315211,China;Ningbo Zhongchun Hi-Tech Co.,Ltd,Ningbo 315042,China)

机构地区：[1]宁波大学土木与环境工程学院,浙江宁波315211 [2]宁波中淳高科股份有限公司,浙江宁波315042

出　　处：《建筑结构学报》2022年第8期293-302,共10页Journal of Building Structures

基　　金：浙江省自然科学基金项目(LGG21E080005);国家自然科学基金项目(51778303)。

摘　　要：针对深厚软土地区静钻根植桩技术应用时水泥土固化效果差的问题,提出了在桩侧设置竖向排水通道并联合真空负压排水固结的静钻根植排水桩技术。介绍了该技术提出的背景、技术方法和特色优势;选取两种不同规格桩型,开展排水桩与传统桩对比模型试验,测试真空负压排水固结和土中孔压发展变化,检测不同桩型的承载力并开展分析。结果表明:桩周水泥土和临近土体中的水部分被抽出,抽水率逐步减小;真空负压逐渐传递到临近土体,使其发生排水固结、强度增加;排水桩加快了水泥土固化,由此提高桩基早期承载力和抗变形能力;相比于传统桩,排水桩28 d的极限承载力提升7%,刚度系数提升40%;排水桩使桩周土体更多地参与荷载传递,桩基破坏模式趋向于整体剪切破坏。The application of statical-drill and rooted pile in deep soft soil areas may encounter the problem of slow cement soil solidification. Thus, a novel technology with the combination of statical-drill and rooted pile and vacuum pressure consolidation was proposed. The background, technical methods and characteristic advantages of this technology were introduced. Comparative model tests for two different types of drainage piles and traditional piles were carried out. The bearing characteristics of different piles were compared and analyzed based on the test data of drainage consolidation process and pore water pressure. The results show that the water in cement soil and the adjacent soil are decreased and the water pumping rate shows a declining trend with time. The vacuum pressure is gradually transferred to the adjacent soil, resulting in an increase of the strength of the surrounding soil due to consolidation. The drainage pile technology accelerates the solidification of cement soil, thereby improving the early bearing capacity and the ability to resist deformation. Compared with traditional piles, the bearing capacity of drainage piles after 28 days increases by 7%, and the stiffness coefficient increases by 40%. Moreover, the drainage pile makes the surrounding soil more involved in load transfer, and the failure mode of the pile tends to be overall shear failure.

关 键 词：静钻根植桩 真空负压 排水固结 模型试验 承载力 

分 类 号：TU473[建筑科学—结构工程] TU476[建筑科学—土工工程]