针对膨胀土中墙后铺设聚苯乙烯泡沫(EPS)缓冲层的悬臂式挡墙,探究了膨胀土因降雨入渗产生膨胀时EPS缓冲层的减压效果。对南阳中膨胀土开展膨胀特性试验,确定其在侧限和竖向荷载作用下的膨胀系数;在此基础上,利用ABAQUS数值软件对膨胀土-EPS缓冲层-悬臂式挡墙体系开展数值分析,研究了EPS缓冲层的厚度与弹性模量及与墙体和膨胀土间摩擦对该支护结构受力变形特征的影响规律。结果表明:EPS缓冲层能有效减小悬臂式挡墙上的侧压力并改变墙背土压力的分布;厚度较厚、弹性模量较低的EPS缓冲层减载效果更好;EPS缓冲层与墙体、膨胀土之间的摩擦影响墙背侧压力的分布,但不影响侧压力的合力大小;EPS缓冲层的压缩刚度与其减载性能成反比。
Abstract
The decompression effect of expanded polystyrene (EPS) buffer layer in cantilever retaining wall was examined when the expansive soil expands due to rainfall infiltration. The expansion characteristics of Nanyang expansive soil were tested to determine its expansion coefficient under lateral and vertical loads. On this basis, the expansive soil-EPS buffer layer-cantilever retaining wall system was numerically simulated using ABAQUS to explore the influences of EPS buffer layer (thickness, elastic modulus, and interface friction) on the stress and deformation of the system. Numerical results indicate that EPS buffer layer effectively reduces the lateral pressure on the cantilever retaining wall and changes the distribution of soil pressure on the wall back. The EPS buffer layer with larger thickness and lower elastic modulus has better effect. The friction between EPS buffer layer, wall and expansive soil affects the distribution of lateral pressure on the wall, but does not affect the resultant force of the lateral pressure. In addition, the compression stiffness of EPS buffer layer is inversely proportional to its load reduction performance.
关键词
膨胀土 /
聚苯乙烯泡沫(EPS) /
悬臂式挡墙 /
数值模拟 /
土压力
Key words
expansive soil /
Expanded Polystyrene (EPS) /
flexible cantilever retaining wall /
numerical simulation /
earth pressure
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] MOHAMED O Z, TAHA Y K, EI-AZIZ E M. Field Study of the Distribution of Lateral Swelling Pressure of Expansive Soil on Retaining Structure[J]. Journal of Engineering Science, 2014, 42(2): 289-302.
[2] 王秉勇. 裂土地区挡土墙上承受的膨胀力分析[J]. 路基工程, 1993(4): 5-11.
[3] AYTEKIN M. Numerical Modeling of EPS Geofoam Used with Swelling Soil[J]. Geotextiles and Geomembranes, 1997, 15(1): 133-146.
[4] AYTEKIN M, VEKLI M, IKIZLER S B. Reductions in Swelling Pressure of Expansive Soil Stabilized Using EPS Geofoam and Sand[J]. Journal of Civil and Environmental Engineering, 2009, 16(3): 216-221.
[5] ERTUGRUL O L, TRANDAFIR A C. Lateral Earth Pressures on Flexible Cantilever Retaining Walls with Deformable Geofoam Inclusions[J]. Engineering Geology, 2013, 158(5): 23-33.
[6] 葛春兰, 邹维列, 夏熙临, 等. EPS用于膨胀土渠坡稳定的压缩与蠕变特性试验研究[J]. 长江科学院院报, 2014, 31(9): 65-68,73.
[7] 郑俊杰, 吕思祺, 曹文昭, 等. 高填方膨胀土作用下刚柔复合桩基挡墙结构数值模拟[J]. 岩土力学, 2019, 40(1): 395-402.
[8] 缪协兴, 杨成永, 陈至达. 膨胀岩体中的湿度应力场理论[J]. 岩土力学, 1993, 14(4): 49-55.
[9] 姬译名, 赵晓彦. 南百铁路钢管格栅膨胀土挡墙数值模拟研究[J]. 高速铁路技术, 2019, 10(2): 60-66,95.
[10] GB 50112—2013, 膨胀土地区建筑技术规范[S]. 北京:中国建筑工业出版社, 2013.
[11] 万梁龙, 张凤德, 王远明,等. 一种固结仪减阻垫块: 中国, ZL 201720178428.4[P]. 2017-11-10.
[12] 万梁龙. 聚苯乙烯泡沫(EPS)减小膨胀土挡墙侧压力的研究[D]. 武汉: 武汉大学, 2019.
[13] YOUNAN A H, VELETSOS A S. Dynamic Response of Flexible Retaining Walls[J]. Earthquake Engineering & Structural Dynamics, 2000, 29(12): 1815-1844.
[14] JTG D30—2008, 公路挡土墙设计与施工技术细则[S]. 北京:人民交通出版社, 2008.
[15] HORVATH J S. The Compressible Inclusion Function of EPS Geofoam[J]. Geotextiles and Geomembranes, 1997, 15(1/2/3):77-120.
[16] TANG N H, LEI D, HUANG D W, et al. Mechanical Performance of Polystyrene Foam (EPS): Experimental and Numerical Analysis[J]. Polymer Testing, 2019, 73: 359-365.
[17] UMUD E O, GUNAY A. Finite Element Analysis of Expanded Polystyrene Foam under Multiple Compressive Loading and Unloading[J]. Materials & Design, 2011, 32(2): 773-780.
[18] 阳云华, 赵 旻, 郭 伟, 等. 南阳盆地膨胀土大气影响深度及其工程意义[J]. 人民长江, 2007, 38(9): 11-13.
[19] 王 钊. 土工合成材料[M]. 北京: 机械工业出版社, 2005.
基金
国家重点研发计划项目(2019YFC1509803);国家自然科学基金项目(51979206,51809199)
PDF(7385 KB)
