作者：王静1，肖涛2，朱鸿鹄1，梅国雄2，刘拯源1，魏广庆3
1. 南京大学 地球科学与工程学院，江苏 南京 210023；
2. 广西大学 土木建筑工程学院，广西 南宁 530004；
3. 苏州南智传感科技有限公司，江苏 苏州 215123
来源：岩土力学, 2021, 42(7): 1961-1970.
摘 要：在软土地基中设置透水管桩可以加快沉桩引起的超静孔隙水的消散速率，进而加速桩周土的固结。目前国内外对透水管桩承载力和透水性能的模型试验和数值模拟研究较多，但深入探究桩基承载力的时间效应和荷载传递规律的现场试验研究较少。通过基于光纤布拉格光栅（FBG）的现场静载试验，研究了软土地基中透水管桩桩身应变分布及内力传递规律，并分析了桩身不同位置处桩−土界面超孔隙水压力随时间的变化规律与桩基承载力时间效应的关系。试验结果表明：沉桩结束前期，透水管桩的单桩竖向抗压承载力增长率较高，并且随时间逐渐降低；试验场地条件下，沉桩后10 d内透水管桩承载力的提高主要来源于桩侧摩阻力，10～24 d内桩端阻力对桩基承载力提高的贡献明显增加；桩−土界面的超孔压沿桩深度增加，随着桩端附近超孔压加速消散，土体有效应力增大，桩侧摩阻力和桩端阻力也随之增大。研究成果对软土地基中透水管桩的设计和施工具有一定的指导意义。
关键词：透水管桩；光纤布拉格光栅（FBG）；承载性能；桩基内力；超孔隙水压力
Fiber optic monitoring and bearing capacity analysis of permeable pipe pile in field test
WANG Jing1, XIAO Tao2, ZHU Hong-hu1, MEI Guo-xiong2, LIU Zheng-yuan1, WEI Guang-qing3
1. School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
2. College of Civil Engineering and Architecture, Guangxi University, Nanning, 530004, China
3. Suzhou NanzZee Sensing Technology, Ltd., Suzhou, 215123, China）
Abstract: Permeable pipe piles are used in soft soil foundation to accelerate the dissipation rate of excess pore water pressure induced by pile driving and then to accelerate consolidation of surrounding soils. The relevant studies are mainly model testing and numerical simulation of the bearing capacity and permeability performance of permeable pipe piles. However, few in-depth field tests have been conducted to study the time effect of bearing capacity and load transfer law of permeable pipe piles. Based on the fiber Bragg grating (FBG) technology, the static load tests were carried out to study the strain distributions of a permeable pipe pile in soft soil foundation and the internal force transfer of the pile body. Meanwhile, the relationship between the variation of excess pore water pressure of the pile-soil interface and the time effect of bearing capacity of the permeable pipe pile is analyzed. The test results show that the growth rate of bearing capacity of a single permeable pipe pile under increased vertical loads is higher in the early pile driving stage, and then gradually decreases with time. The increase of bearing capacity of the permeable pipe pile within 10 days under the test site condition is mainly due to the pile skin friction, whereas the pile tip resistance contributes more to the enhancement of bearing capacity within 10-24 days. The excess pore water pressure of the pile-soil interface increases along the pile depth. With the rapid dissipation of the excess pore water pressure near the pile tip, the effective stress of soil gradually increases, and the pile skin friction and pile tip resistance also increase. This study provides an improved insight into the design and construction of permeable pipe piles in soft soil foundation.
Keywords: permeable pipe pile; fiber Bragg grating (FBG); bearing capacity; pile internal force; excess pore water pressure
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引用本文：
王静, 肖涛, 朱鸿鹄, 梅国雄, 刘拯源, 魏广庆, . 透水管桩现场试验光纤监测与承载性能研究[J]. 岩土力学, 2021, 42(7): 1961-1970.
WANG Jing, XIAO Tao, ZHU Hong-hu, MEI Guo-xiong, LIU Zheng-yuan, WEI Guang-qing, . Study on bearing capacity of permeable pipe pile by field optical fiber monitoring[J]. Rock and Soil Mechanics, 2021, 42(7): 1961-1970.