CFG桩单桩承载力离心模型试验与现场试验对比分析

王年香; 刘超; 林显才; 曹昌浩; 连长秋

doi:10.11779/CJGE2022S2002

CFG桩单桩承载力离心模型试验与现场试验对比分析 English Version

王年香^{1, 2,},
刘超³,
林显才³,
曹昌浩⁴,
连长秋⁴

1.
南京水利科学研究院岩土工程研究所, 江苏南京 210024
2.
水文水资源与水利工程国家重点实验室, 江苏南京 210029
3.
湛江港(集团)股份有限公司, 广东湛江 524068
4.
广东省航运规划设计院有限公司, 广东广州 510050

基金项目:

中央级公益性科研院所基本科研业务费专项资金项目 Y321006

中央级公益性科研院所基本科研业务费专项资金项目 Y321007

详细信息

作者简介:
王年香（1963—），江西信丰人，博士，正高级工程师，主要从事岩土工程基本理论和试验研究工作。E-mail: nxwang@nhri.cn

中图分类号: TU435
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出版历程
- 收稿日期: 2022-12-07
- 网络出版日期: 2023-03-26
- 刊出日期: 2022-11-30

Comparative analysis of bearing capacity of CFG single pile by centrifugal model tests and field tests

1.
Geotechnical Engineering Department, Nanjing Hydraulic Research Institute, Nanjing 210024, China
2.
State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing 210029, China
3.
Zhanjiang Port (Group) Co. LTD, Zhanjiang 524068, China
4.
Guangdong Province Planning and Design Institute for Water Transportation Co. LTD, Guangzhou 510050, China

摘要

摘要: 某码头堆场软土地基发生了推移，在典型区采用CFG桩网复合地基进行加固。通过CFG桩离心模型试验和现场静载试验，研究了CFG桩单桩承载性状，对比分析了离心模型试验和现场静载试验的单桩承载变形差异，并与规范方法计算的单桩竖向极限承载力进行了比较。结果表明，离心模型试验和现场静载试验的Q–s曲线均存在比较明显的差异，离心模型试验得出的单桩极限承载力大于现场静载试验，两者的最大试验荷载基本一致，单桩竖向极限承载力计算值低于离心模型和现场静载试验值。
- CFG桩 /
- 单桩承载力 /
- 离心模型试验 /
- 现场静载试验
Abstract: For the soft soil foundation slipped in the storage yard of a wharf, the composite foundation with CFG pile net is used for reinforcement in typical zone. The centrifugal model tests and field static load tests are carried out to study the bearing behavior of CFG pile. The bearing deformation difference of single pile between the centrifugal model tests and the field static load tests is compared and analyzed. The test results of the vertical ultimate bearing capacity of single pile are compared with the calculated ones by the method recommended by China's technical code for composit foundation. The results show that there are obvious differences between the Q-s curves of the centrifugal model tests and field static load tests. The ultimate bearing capacity of single pile of the centrifugal model tests is greater than that of the field static load tests, and their maximum test loads are basically the same. The calculated values of the vertical ultimate bearing capacity of single pile are lower than those of the centrifugal model tests and field static load tests.
- CFG pile /
- bearing capacity of single pile /
- centrifugal model test /
- field static load test

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图 1 离心模型试验布置图

Figure 1. Layout of centrifugal model tests

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图 2 4根CFG桩离心模型试验Q–s曲线

Figure 2. Q–s curve of centrifugal model tests on 4 CFG piles

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图 3 CFG桩单桩静荷载试验Q–s曲线

Figure 3. Q–s curves of static load tests on single CFG pile

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图 4 CFG桩单桩静荷载试验s–lgt曲线

Figure 4. s–lgt curves of static load tests on single CFG pile

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表 1 土的物理力学性质指标

Table 1 Physical and mechanical properties of soils

土名	厚度/m	含水率/%	密度/(g·cm^-3)	不排水强度/kPa	地基承载力特征值/kPa	混凝土预制桩		泥浆护壁钻（冲）孔桩
土名	厚度/m	含水率/%	密度/(g·cm^-3)	不排水强度/kPa	地基承载力特征值/kPa	桩的极限侧阻力标准值/kPa	桩的极限端阻力标准值/kPa	桩的极限侧阻力标准值/kPa	桩的极限端阻力标准值/kPa
①₂素填土	2.5	32.0	1.91	25	150	28		25
②₁淤泥质黏土	6.2	50.8	1.72	31	60	22		20
③₄粉质黏土	3.5	31.0	1.92	41	210	65	1000	60	450
③₂中粗砂	1.7		1.85		220	75	2400	60	1100
④₁黏土	3.2	42.3	1.77	51	200	65	900	60	500
④₂黏土		41.6	1.72	51	220	75	1400	60	700

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表 2 离心模型试验与现场静载试验结果对比

Table 2 Comparison of results of centrifugal model tests and field static load tests

试验方法与桩号	离心模型试验	现场静载试验
试验方法与桩号	离心模型试验	SZ2-2	SZ2-3	SZ2-6
桩长/m	16	15	17	17
单桩极限承载力/kN	1055	800	800	1000
沉降/mm	42.10	18.49	42.56	26.27
刚度/kN·mm^-1	25.06	43.27	18.80	38.07
最大荷载/kN	1090	1000	1000	1100
最大沉降/mm	66.36	87.74	221.18	185.14

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表 3 试验与计算的单桩极限承载力对比

Table 3 Comparison between test and calculated ultimate bearing capacities of single pile (单位: kN)

离心模型试验	现场静载试验	按浆护壁钻孔桩计算	按混凝土预制桩计算
1055	850	735	857

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