为了研究真空负压抽排水时间对静钻根植排水桩承载特性的影响,开展了多组不同抽排水时间情况下静钻根植排水桩和静钻根植桩模型试验,对比测试了孔压发展变化和不同阶段的桩基承载力。结果表明:抽真空过程中,排水桩桩周孔压在前8 h内消散速率较快,随后逐渐变缓;相较于静钻根植桩,真空负压抽排水3、8、72 h后28 d,静钻根植排水桩桩基的极限承载力分别提高了56%、61%、74%,抗变形能力分别提高了10.2%、89.8%、124.5%。抽排水能够显著加快水泥土固化时间,提高桩周土体强度特性,进而提高静钻根植排水桩的承载力和抗变形能力,因此具有较好的推广价值。
Abstract
The aim of this research is to investgate the influence of pumping and drainage time on the bearing characteristics of static drill rooted drainage pile. Several groups of model tests of static drill rooted drainage pile and ordinary static drill rooted pile were performed with pumping and drainage time as the variable to compare the change of pore pressure and the bearing capacity of pile foundation at different stages. Results show that in the process of vacuum-pumping, the pore pressure around drainage pile dissipates rapidly within the first eight hours, and then slows down gradually. Compared with that of ordinary static drill rooted pile, the ultimate bearing capacity of drainage pile foundation after vacuum negative pressure pumping and drainage for 3 hours, 8 hours, and 72 hours, increases by 56%, 61%, and 74%, respectively, and the anti-deformation ability increases by 10.2%, 89.8% and 124.5%, respectively. Pumping and drainage has a good popularizing value as it significantly accelerates the cement-soil solidification, improves the mechanical properties of soil around the pile, and then enhances the bearing capacity and anti-deformation capacity of the pile foundation.
关键词
静钻根植排水桩 /
模型试验 /
抽排水时间 /
水泥土 /
承载力
Key words
static drill rooted drainage pile /
model test /
drainage time /
cement soil /
bearing capacity
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 张日红, 吴磊磊, 孔清华. 静钻根植桩基础研究与实践[J]. 岩土工程学报, 2013, 35(增刊2): 1200-1203.
[2] 龚晓南, 解 才, 周佳锦, 等. 静钻根植竹节桩抗压与抗拔对比研究[J]. 上海交通大学学报, 2018, 52(11): 1467-1474.
[3] 王奎华, 李振亚, 吕述晖, 等. 静钻根植竹节桩纵向振动特性及应用研究[J]. 浙江大学学报(工学版), 2015, 49(3): 522-530.
[4] 王奎华, 肖 偲, 高 柳, 等. 静钻根植竹节桩竖向动力响应研究[J]. 振动与冲击, 2019, 38(15): 49-56, 86.
[5] 周佳锦, 龚晓南, 王奎华, 等. 静钻根植竹节桩荷载传递机理模型试验[J]. 浙江大学学报(工学版), 2015, 49(3): 531-537, 546.
[6] 周佳锦, 王奎华, 龚晓南, 等. 静钻根植竹节桩桩端承载性能试验研究[J]. 岩土力学, 2016, 37(9): 2603-2609.
[7] 周佳锦, 龚晓南, 严天龙, 等. 软土地区填砂竹节桩抗压承载性能研究[J]. 岩土力学, 2018, 39(9): 3425-3432.
[8] 周佳锦, 张日红, 黄 晟, 等. 软土地区预应力竹节桩与管桩抗压承载性能研究[J]. 天津大学学报(自然科学与工程技术版), 2019, 52(增刊1): 9-15.
[9] 吴燕开, 方 磊, 李新伟, 等. 预应力管桩联合塑料排水板加固软土地基技术探讨[J]. 岩石力学与工程学报, 2006, 25(增刊2): 3572-3576.
[10] 刘孝江. 水泥搅拌桩和塑料排水板联合处理软基的试验研究和工程应用[D]. 南京: 南京林业大学, 2005.
[11] LIU H L, CHEN Y M, ZHAO N. Development Technology of Rigidity-Drain Pile and Numerical Analysis of Its Anti-liquefaction Characteristics[J]. Journal of Central South University of Technology, 2008, 15(2): 101-107.
[12] 雷金波, 杨金尤, 李壮状, 等. 带帽有孔管桩复合地基承载力模型试验研究[J]. 建筑结构学报, 2018, 39(11): 171-179.
[13] 邓岳保, 张日红, 孙嘉烽, 等. 静钻根植排水桩技术及模型试验研究[J]. 建筑结构学报, 2022, 43(8): 293-302.
[14] JGJ 106—2014,建筑基桩检测技术规范[S]. 北京: 中国建筑工业出版社, 2014.
[15] FLEMING K,WELTMAN A,RANDOLPH M,et al. Piling Engineering[M]. Edition 3. Boca Raton:CRC Press,2008.
基金
浙江省自然科学基金项目(LGG21E080005);宁波市重大科技攻关暨揭榜挂帅项目(2022Z030)
PDF(1563 KB)
