智能化双向搅拌粉喷桩加固海相软土地基的力学性能及承载力评价方法研究  

STUDY ON THE EVALUATION METHOD OF MECHANICAL PROPERTIES AND BEARING CAPACITY OF MARINE SOFT SOIL FOUNDATION STRENGTHENED BY INTELLIGENT BI-DIRECTIONAL MIXING POWDER JET PILE

作　　者：邱近哲 杜广印[1,2] 王传乐 杨泳 QIU Jinzhe;DU Guangyin;WANG Chuanle;YANG Yong(School of Transportation,Southeast University,Nanjing 210096,China;Jiangsu Key Laboratory of Urban Underground Engineering and Environmental Safety,Nanjing 210096,China;Jiangsu Shengtai Construction Engineering Co.,Ltd.,Lianyungang 222000,China)

机构地区：[1]东南大学交通学院,南京210096 [2]江苏省城市地下工程与环境安全重点实验室,南京210096 [3]江苏盛泰建设工程有限公司,连云港222000

出　　处：《工程地质学报》2025年第1期377-386,共10页Journal of Engineering Geology

基　　金：江苏省交通科技资助项目(资助号:2022G1-2).

摘　　要：智能化双向搅拌粉喷桩在连云港-宿迁高速公路的海相软土地基处理工程中得到了大面积推广应用。为验证该智能化施工技术的加固效果,对不同龄期的桩体进行了现场原位测试试验,并对取自桩身不同深度处的水泥土芯样开展了不固结不排水三轴剪切和无侧限抗压强度试验。基于现场原位测试及室内力学试验结果,研究了智能化双向搅拌粉喷桩水泥土的强度指标,提出了依托工程场地条件下粉喷桩单桩和复合地基承载力的计算方法。研究结果表明:该智能化双向搅拌粉喷桩桩体强度高,桩身均匀,成桩质量较好;水泥土剪切峰值强度与围压呈线性正相关,基于Mohr-Coulomb强度准则得到在7 d、14 d和28 d时水泥土芯样的黏聚力c分别为402.9 kPa、557.3 kPa和593.1 kPa,内摩擦角φ分别为35.8°、36.8°和39.9°;芯样无侧限抗压强度与桩身标准贯入击数线性相关,且两者与龄期均满足对数函数关系;依据提出的复合地基承载力计算方法,算得桩间距1.4 m和1.2 m处的粉喷桩复合地基地基承载力分别为137 kPa和177 kPa,该计算结果与现场载荷试验结果较为相近,证明了本文复合地基承载力计算方法的准确性和适用性,同时验证了智能化双向搅拌粉喷桩的地基加固效果。The intelligent bidirectional deep mixed cement spray pile has been widely applied in the marine soft soil foundation of the Lianyungang-Suqian expressway project.In-situ tests were conducted on piles at different ages,and unconsolidated and undrained triaxial shear and uniaxial compressive tests were performed on soil-cement samples taken from different depths of the pile to verify the reinforcement effect of the intelligent construction technology.Based on the in-situ and laboratory mechanical tests,the strength index of the mixed cement piles was studied,and the bearing capacity of the single pile and composite foundation was deduced.The research results show that the intelligently mixed pile has high strength,a uniform pile body,and good pile quality.There is a linear positive relationship between the shear strength and the confining pressure of the soil-cement pile.Based on the Mohr-Coulomb strength criterion,the cohesive forces of soil-cement core samples at 7,14,and 28 days were 402.9 kPa,557.3 kPa,and 593.1 kPa,respectively,while the internal friction angles were 35.8°,36.8°,and 39.9°,respectively.The uniaxial compressive strength of the sample is linearly related to the standard penetration number,and both meet a logarithmic function relationship with age.According to the composite foundation calculation method proposed in this paper,the foundation bearing capacities with pile spacings of 1.4 m and 1.2 m for the expressway project are 137 kPa and 177 kPa,respectively.The calculated results are close to the field load test results,which verifies the accuracy and applicability of the formula proposed in this study.At the same time,the foundation reinforcement effect of the intelligent bidirectional mixing powder spray pile is also verified.

关 键 词：智能化 双向搅拌桩 三轴剪切试验 原位测试 地基承载力 

分 类 号：TU447[建筑科学—岩土工程]