Centrifugal model tests on micro-pile-reinforced shallow foundation in layered soils
-
摘要: 对比了成层地基微型桩加固浅基础与不加固情况的离心模型试验，分析地基土和基础的变形破坏响应，阐明复杂地层条件下微型桩的加固机理。结果表明微型桩显著减小了浅基础的沉降量。微型桩加固的主要范围在淤泥质粉质黏土层深度4 m上方。微型桩加固下，地基的沉降更为规律均匀，粉质黏土层与淤泥质粉质黏土层的分界层附近位移变化更缓和。微型桩加固下，荷载影响区域深度减小，粉质黏土层影响区域宽度的减小幅度大于淤泥质粉质黏土层。微型桩抑制荷载向下层地层的传导，约束了下层地基的水平位移，提高地基承载力。研究得出的规律为微型桩在现实工程中的应用提供参考。Abstract: The centrifugal model tests are conducted on the micro-pile-reinforced and unreinforced shallow foundations buried in complex formation during vertical loading. The deformations of soil base and the foundation are observed and compared for the micro-pile reinforcement effects. The results show that the micro-piles significantly reduce the settlement of shallow foundations. The main scope of the micro-pile reinforcement is above a depth of 4 m in the silty clay layer. Under the reinforcement of the micro-piles, the settlement of the foundation is more regular and uniform, and the displacement change near the boundary layer between the clay layer and the silty clay layer is more gentle. The depth of the load influence zone decreases if the micro-piles are used, and the width of the influence area of the clay layer is reduced by a greater extent than that of the silty clay layer. The micro-piles suppress the transmission of loads to the lower strata and constrain the horizontal displacement of the soils, thus increase the bearing capacity of shallow foundation. The rules obtained from this study may provide reference for the application of micro-piles in practice.
-
Keywords:
- centrifugal model test /
- complex formation /
- micro-pile /
- bearing capacity
-
-
![]()
图 3 未加固方案地基沉降分布（B，浅基础宽度）
Figure 3. Settlement distribution in horizontal direction of soils for unreinforeced scheme (B, breadth of shallow foundation)
![]()
图 4 加固方案地基沉降分布（B，浅基础宽度）
Figure 4. Settlement distribution in horizontal direction of soils for reinforeced scheme (B, breadth of shallow foundation)
![]()
图 5 未加固方案不同荷载下地基沉降竖直分布
Figure 5. Vertical distribution of soil settlement for unreinforeced foundation under different loading levels
![]()
图 6 加固方案不同荷载下地基沉降竖直分布
Figure 6. Vertical distribution of soil settlement for reinforeced foundation under different loading levels
![]()
图 9 加固与未加固方案地基水平位移分布（荷载：6.4 MN）
Figure 9. Horizontal distribution of horizontal displacements for reinforced and unreinforced foundations (load: 6.4 MN)
表 1 原型与模型尺寸对应表
Table 1 Specific parameters of prototype and model
参数 原型/m 模型/mm 条形基础宽度 2.00 50.0 条形基础高度 1.33 33.3 条形基础埋深 0.668 16.7 微型桩桩径 0.20 5.0 微型桩桩长 10 250.0 微型桩桩距 1.6 40.0 微型桩与条形基础边距 0.232 5.8 粉质黏土层厚度 4 100.0 淤泥质粉质黏土层厚度 14 350.0 托梁（铝）宽度 2.868 71.7 托梁高度 0.668 16.7 托梁埋深 0.0 0.0 
下载: 导出CSV
-
[1] BRUCE D A, DIMILLIO A F, JURAN I. Introduction to micropiles: an international perspective[M] //Geotechnical Special Publication, ASCE, 1995: 1-26.
[2] YAN J, LIU X, ZHANG Z, et al. Model test of micro-pile group reinforcing high steep landslide[J]. Applied Sciences, 2022, 12(19): 10017. doi: 10.3390/app121910017
[3] ELSAWWAF A, EL SAWWAF M, FAROUK A, et al. Restoration of tilted buildings via micropile underpinning: a case study of a multistory building supported by a raft foundation[J]. Buildings, 2023, 13(2): 422. doi: 10.3390/buildings13020422
[4] 李子曦, 罗方悦, 张嘎. 微型桩加固浅基础的离心模型试验研究[J]. 岩土工程学报, 2021, 43(增刊2): 56-59. doi: 10.11779/CJGE2021S2013 LI Zixi, LUO Fangyue, ZHANG Ga. Centrifugal model tests on micro-pile-reinforced shallow foundation[J]. Chinese Journal of Geotechnical Engineering, 2021, 43(S2): 56-59. (in Chinese) doi: 10.11779/CJGE2021S2013
[5] BORTHAKUR N, DEY A K, et al. Evaluation of group capacity of micro-pile in soft clayey soil from experimental analysis using SVM-based prediction model[J]. International Journal of Geomechanics, 2020, 20(3): 04020008. doi: 10.1061/(ASCE)GM.1943-5622.0001606
[6] TSUKADA Y, MIURA K, TSUBOKAWA Y, et al. Mechanism of bearing capacity of spread footings reinforced with micropiles[J]. Soils and Foundations, 2006, 46(3): 367-376. doi: 10.3208/sandf.46.367
[7] RICHARDS T D Jr, ROTHBAUER M J. Lateral loads on pin piles (micropiles)[C]// GeoSupport 2004. Orlando, 2004.
[8] 董睿文. 超大直径泥水平衡盾构法在珠海淤泥质粉质黏土地层中的泥水处理技术提升试验研究[J]. 建筑监督检测与造价, 2023, 16(3): 17-23. https://www.cnki.com.cn/Article/CJFDTOTAL-PJZJ202303005.htm DONG Ruiwen. Experimental study on the improvement of slurry treatment technology by extra-large diameter slurry pressure shield method in Zhuhai muddy silty clay layer[J]. Supervision Test and Cost of Construction, 2023, 16(3): 17-23. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-PJZJ202303005.htm
[9] 王年香, 章为民. 土工离心模型试验技术与应用[M]. 北京: 中国建筑工业出版社, 2015. WANG Nianxiang, ZHANG Weimin. Geotechnical Centrifuge Model Test Technology and its Application[M]. Beijing: China Architecture & Building Press, 2015. (in Chinese)
[10] LIU S J, LUO F Y, ZHANG G. Centrifuge model tests on pile-reinforced slopes subjected to drawdown[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2020, 12(6): 1290-1300. doi: 10.1016/j.jrmge.2020.02.006
[11] ZHANG G, HU Y, ZHANG J M. New image analysis-based displacement-measurement system for geotechnical centrifuge modeling tests[J]. Measurement, 2009, 42(1): 87-96. doi: 10.1016/j.measurement.2008.04.002
计量
- 文章访问数: 108
- HTML全文浏览量: 27
- PDF下载量: 16
