加筋土挡墙由于优良的力学性能、低廉的造价、更好的地形适应性,已经越来越广泛地被应用于各种工程。但其在正常工作状态下的真正工作机理尚不完全清楚,目前的规范设计指南并不能反映加筋土挡墙内部应力真实分布情况。为了研究不同筋材刚度对加筋土挡墙性能的影响,通过土工离心试验监测了土工格栅应变、面板水平位移和土压力。试验结果表明:采用小刚度筋材时,筋材的变形更加显著,但对竖向土压力的分布基本没有影响;靠近面板区域的土压力都远小于理论值,格栅最大应变出现在墙的中下部;对于面板连接处的筋材应变不能简单地用传统土压力理论解释,还需考虑填土不均匀沉降引起的面板对加筋土拉拽作用等其他影响因素。试验结果可为正常工况下加筋土挡墙工作性能与筋-土相互作用机理的研究提供参考。
Abstract
Reinforced soil retaining wall has been widely used in various projects because of its excellent mechanical properties, lower costs and better terrain adaptability. However, its real mechanism under working stress condition is not completely clear and current design guidelines could not reflect the real stress distribution in reinforced retaining wall. In order to research the behavior of reinforced retaining wall with different reinforcement stiffness, we monitor geogrid strain, horizontal displacement of facing, and earth pressure by geotechnical centrifuge tests. Results indicate that the deformation of reinforcement is more significant when using reinforcement of small stiffness,while the distribution of vertical earth pressure along the potential sliding surface is barely affected by stiffness. In both models, earth pressure adjoining to facing panel is much lower than theoretical value, and the maximum strain of geogrid appears in the mid-lower part of wall. Traditional earth pressure theory could not simply explain the reinforcement strain at panel connections. We should also take into account the pulling effect between panel and reinforced soil induced by differential settlement of backfill and other factors. The tests results offer reference for researching the behavior of reinforced soil retaining wall and the mechanism of interaction between soil and reinforcement under working stress conditions.
关键词
加筋土挡墙 /
土工离心试验 /
筋材刚度 /
土工格栅应变 /
土压力
Key words
reinforced soil retaining wall /
geotechnical centrifugal test /
stiffness of reinforcement /
strain of geogrid /
earth pressure
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 包承纲. 我国岩土离心模拟技术的应用与发展[J]. 长江科学院院报,2013,30(11): 55-66.
[2] 李广信. 关于土工合成材料加筋设计的若干问题[J]. 岩土工程学报,2013,35(4): 605-610.
[3] AASHTO. AASHTO LRFD Bridge Design Specifications[S].Washington, D.C., USA:American Association of State Highway and Transportation Officials,2012.
[4] BS8006-1:2010,Code of Practice for Strengthened/Reinforced Soils and Other Fills [S]. London, UK: British Standards Institution, 2010.
[5]NCMA. Design Manual for Segmental Retaining Walls-second edition[S]. Washington, D.C: National Concrete Masonry Association, 1997.
[6] DIBt. German Code of Practice for the Design of Reinforced Soil Structures [S]. German: Deutches Institute fur Bautechnik, 1997.
[7] TB 10118—2006,铁路路基土工合成材料应用设计规范[S]. 北京:中国铁道出版社,2006.
[8] GB/T 50290—2014,土工合成材料应用技术规范[S].北京:中国计划出版社,2015.
[9] FHWA-NHI-10-024, Design and Construction of Mechanically Stabilized Earth Walls and Reinforced Soil Slopes-Volume 1[S]. Washington, D.C: Federal Highway Administration and U.S. Department of Transportation,2009.
[10]SHARMA J S, BOLTON M D. Centrifuge Modeling of an Embankment on Soft Clay Reinforced with a Geogrid[J]. Geotextiles and Geomembranes, 1996,14(1):1-17.
[11]SHARMA J S,BOLTON M D. Centrifugal and Numerical Modeling of Reinforced Embankments on Soft Clay Installed with Wick Drains[J]. Geotextiles and Geomembranes,2001,19(1):23-44.
[12]俞松波,沈明荣,陈建峰,等. 离心模型试验中土工格栅拉力测量[J]. 岩石力学与工程学报,2008,27(11): 2295-2301.
[13]RAISINGHANI D V, VISWANADHAM B V S. Centrifuge Model Study on Low Permeable Slope Reinforced by Hybrid Geosynthetics[J]. Geotextiles and Geomembranes,2011, 29(6): 567-580.
[14]徐 超,贾 斌,罗玉珊. 间接加筋作用及加筋土挡墙离心模型试验验证[J]. 水文地质工程地质,2015,42(2): 77-82.
[15]COSTA C M L, ZORNBERG J G, BUENO B D S, et al. Centrifuge Evaluation of the Time-dependent Behavior of Geotextile-reinforced Soil Walls[J]. Geotextiles and Geomembranes,2016, 44(2): 188-200.
[16]朱海龙,刘一通,邢义川,等. 加筋土挡墙破坏形式的离心模型试验研究[J]. 长江科学院院报,2014, 31(3): 58-64.
[17]BALAKRISHNAN S, VISWANADHAM B V S. Performance Evaluation of Geogrid Reinforced Soil Walls with Marginal Backfills through Centrifuge Model Tests [J]. Geotextiles and Geomembranes,2016, 44(1): 95-108.
[18]ALLEN T M, BATHURST R J, HOLTZ R D,et al. A New Working Stress Method for prediction of Reinforcement Loads in Geosynthetic Walls[J]. Canadian Geotechnical Journal, 2003, 40(5): 976-994.
[19]ALLEN T M, BATHURST R J. Performance of an 11m High Block-faced Geogrid Wall Designed using the K-stiffness Method[J]. Canadian Geotechnical Journal, 2014, 51(1): 16-29.
[20]LIU H. Reinforcement Load and Compression of Reinforced Soil Mass under Surcharge Loading[J]. Journal of Geotechnical & Geoenvironmental Engineering, 2015,141(6): 04015017.
[21]LIU H. Nonlinear Elastic Analysis of Reinforcement Loads for Vertical Reinforced Soil Composites without Facing Restriction [J]. Journal of Geotechnical & Amp Geoenvironmental Engineering, 2016,142(6): 04016013.
PDF(3692 KB)
