Eexperimental study of the bearing capacity of existing pile foundation in silty clay stratum promoted by pile side grouting
ZHOU Yong1, LI Zhaofeng2, ZUO Zhiwu1, WANG Chuan1,2, WANG Yuxin2, LIN Chunjin2, ZHANG Xin3, ZHANG Qianqing2, YAO Wang3, WANG Kai3
1. Shandong High Speed Group Co., Ltd., Jinan 250101, Shandong, China;
2. Geotechnical and Structural Engineering Research Center, Shandong University, Jinan 250061, Shandong, China;
3. Shangdong Hi-speed Company Limited, Jinan 250014, Shandong, China
Abstract: Aiming at the problem of insufficient bearing capacity of existing pile foundation in silty clay stratum, the effect of improving bearing capacity of existing pile foundation by side grouting was studied systematically through grouting simulation experiment. The reinforcement mechanism was mainly through the compaction effect of grouting material on the soil around the pile, increasing the friction resistance of the pile-soil interface, restricting the settlement of the pile body, and improving the bearing capacity of the pile foundation. The results showed that the grouting water cement ratio, grouting pressure, grouting hole layout position and grouting amount were the four main controlling factors for the reinforcement effect of pile foundation. The combined action of slurry water-cement ratio and grouting pressure directly affected the compaction effect of slurry on silty clay stratum by controlling the shape of slurry veins. According to the different compaction effects, the combination of different water cement ratio and grouting pressure was divided into three reinforcement design areas: strong, medium and weak. Among them, the compacted soil with a slurry water-cement ratio of 0.8 and a grouting pressure of 2 MPa improved the physical and mechanical strength to the greatest extent. The increase of the bearing capacity of pile foundation was positively correlated with the amount of grouting, and inversely proportional to the distance between the formation position of grouting vein and the pile body. According to the different distance between the formation position of grouting vein and the pile body, the soil reinforced by grouting was divided into the strong action area and the weak action area. In addition, the improvement of lateral friction resistance of pile side grouting was mainly generated in the middle and lower section of pile body. In practical engineering, the reinforcement of this section reduced the consumption of manpower and material resources.
周勇, 李召峰, 左志武, 王川, 王钰鑫, 林春金, 张新, 张乾青, 姚望, 王凯. 桩侧注浆提升粉质黏土地层既有桩基承载力试验研究[J]. 隧道与地下工程灾害防治, 2022, 4(1): 38-47.
ZHOU Yong, LI Zhaofeng, ZUO Zhiwu, WANG Chuan, WANG Yuxin, LIN Chunjin, ZHANG Xin, ZHANG Qianqing, YAO Wang, WANG Kai. Eexperimental study of the bearing capacity of existing pile foundation in silty clay stratum promoted by pile side grouting. Hazard Control in Tunnelling and Underground Engineering, 2022, 4(1): 38-47.
[1] 余文章,李向清,庞金波. 软弱土地基不均匀沉降的桩基加固应用及研究[J]. 工程质量, 2018, 36(8): 48-51. YU Wenzhang, LI Xiangqing, PANG Jinbo. The application and research of pile foundation reinforcement for differential settlement of soft soil foundation[J]. Construction Quality, 2018, 36(8): 48-51. [2] 傅强. 注浆法在卵石地质旧桥桩基加固中的应用[J]. 工程与建设, 2008, 22(5): 684-686. FU Qiang. Application of grouting method in old pebble-geological bridge pile foundation reinforcement[J]. Engineering and Construction, 2008, 22(5): 684-686. [3] 朱慈祥,汪志春,徐浪, 等. 运营桥梁抬桩加固既有桩基础沉降分析及监测研究[J]. 世界桥梁, 2018, 46(3): 86-90. ZHU Cixiang, WANG Zhichun, XU Lang, et al. Analysis and monitoring for pile foundation subsidence of a bridge in service strengthened by adding piles[J]. World Bridges, 2018, 46(3): 86-90. [4] 李长城.基于济青高速公路改扩建环境特点的桥梁加固施工思路探索[J].智能城市,2019,5(24):146-147. [5] 柳琪. 压力注浆在桥梁桩基础加固中的应用[J]. 城市道桥与防洪, 2014(1): 75-77. LIU Qi. Application of pressure grouting in reinforcement of bridge pile foundation[J]. Urban Roads Bridges & Flood Control, 2014(1): 75-77. [6] 黄秀珠. 增补桩基加固技术在墩柱盖梁裂缝病变桥梁的应用探讨[J]. 西部交通科技, 2018(8): 100-104. HUANG Xiuzhu. Application of supplementary pile foundation reinforcement technology in the cracking damage of bridge pier cap beams[J]. Western China Communications Science & Technology, 2018(8): 100-104. [7] 张利鹏. 非湿陷性黄土地区不同成孔方式桩端后压浆灌注桩承载特性研究[D]. 西安: 长安大学, 2018. ZHANG Lipeng. Study on bearing performance of the post-grouting piles with different hole-forming methods in non collaosible loess area[D]. Xi'an: Chang'an University, 2018. [8] 李术才,陈红宾,张晓, 等. 粉质黏土隧道超前支护效应试验研究[J]. 中南大学学报(自然科学版), 2019, 50(4): 946-956. LI Shucai, CHEN Hongbin, ZHANG Xiao, et al. Experimental study on advanced support effect in silty clay tunnel[J]. Journal of Central South University(Science and Technology), 2019, 50(4): 946-956. [9] 赵春风, 吴悦, 赵程, 等. 黏土中桩端后注浆单桩抗压承载特性室内模型试验研究[J]. 天津大学学报(自然科学与工程技术版), 2019, 52(12):1235-1244. ZHAO Chunfeng, WU Yue, ZHAO Cheng, et al. Indoor model tests on the compressive bearing behavior of a single pile in clay with pile end post-grouting[J]. Journal of Tianjin University(Science and Technology), 2019, 52(12):1235-1244. [10] 刘奇,陈卫忠,袁敬强, 等. 岩溶充填黏土注浆加固试验研究[J]. 岩石力学与工程学报, 2019, 38(增刊1): 3179-3188. LIU Qi, CHEN Weizhong, YUAN Jingqiang, et al. Laboratory experiment study of grouted materials filled in Karst caverns[J]. Chinese Journal of Rock Mechanics and Engineering, 2019, 38(Suppl.1): 3179-3188. [11] 张文学, 刘海陆, 谢全懿. 岩溶区桩基注浆加固效果的影响因素分析[J]. 铁道建筑, 2014, 54(7): 28-30. ZHANG Wenxue, LIU Hailu, XIE Quanyi. Affected factors analysis of pile foundation grouting reinforcing effect in Karst region[J]. Railway Engineering, 2014, 54(7): 28-30. [12] 郑昭瑜. CFG桩软基加固质量缺陷原因分析及处理方法探讨[J]. 四川建材, 2018, 44(12): 100-101. [13] 罗根传,何忠明,曾铃. 高速公路改扩建工程边坡抗滑桩加固效果数值分析[J]. 中南大学学报(自然科学版), 2015, 46(6): 2244-2249. LUO Genchuan, HE Zhongming, ZENG Ling. Numerical analysis of reinforcement effect of slope anti-slide pile on expressway reconstruction projection[J]. Journal of Central South University(Science and Technology), 2015, 46(6): 2244-2249. [14] 肖东, 蒋关鲁, 林展展, 等. 过渡段地基加固作用对桥台桩工作性状的影响分析[J]. 中南大学学报(自然科学版), 2017, 48(3): 820-829. XIAO Dong, JIANG Guanlu, LIN Zhanzhan, et al. Analysis on working properties of abutment piles considering foundation reinforcement of approach embankment[J]. Journal of Central South University(Science and Technology), 2017, 48(3): 820-829. [15] 凌同华,张胜,李升冉, 等. 邻近隧道施工既有桥桩变形控制及注浆加固方案优化[J]. 中南大学学报(自然科学版), 2014, 45(7): 2394-2400. LING Tonghua, ZHANG Sheng, LI Shengran, et al. Controlling of existing bridge piles deformation induced by adjacent tunneling and scheme of optimizing grouting reinforcement[J]. Journal of Central South University(Science and Technology), 2014, 45(7): 2394-2400. [16] 南京水利科学研究院.土工试验规程:SL237—1999[S]. 北京:中国水利水电出版社,1999. [17] 张健,李召峰,李术才,等. 基于抗崩解特性的全风化花岗岩地层注浆参数设计方法[J]. 工程科学与技术, 2019, 51(5): 87-95. ZHANG Jian, LI Zhaofeng, LI Shucai, et al. Grouting parameters design method of completely weathered granite based on anti-disintegration characteristics[J]. Journal of Sichuan University(Engineering Science Edition), 2019, 51(5): 87-95. [18] 杨磊, 林荣峰, 李召峰, 等. 水泥浆液黏度对全风化花岗岩注浆加固效果的影响[J]. 中国公路学报, 2018, 31(10): 246-254. YANG Lei, LIN Rongfeng, LI Zhaofeng, et al. Influence of grout viscosity on the grouting reinforcement effect of completely weathered granite[J]. China Journal of Highway and Transport, 2018, 31(10): 246-254.
2022, Vol. 4 
