土工模袋砂竖向抗压强度及其影响因素*

开展了不同尺寸、数量及充填度下的模袋砂单轴压缩试验，深入研究模袋砂界面摩擦特性、充填度及尺寸对其抗压强度和破坏机理的影响。基于现有研究成果，推导了综合考虑模袋砂间相互作用和充填度影响的模袋砂抗压强度计算公式。研究结果表明：单个模袋砂试验抗压强度远大于多个模袋砂试验结果，且随充填度的减小愈发显著，因此现有针对单个模袋砂的试验研究存在不足。模袋砂抗压强度随着充填度的增加而减小，尺寸效应对模袋砂受力变形规律影响很小，而对其承载力影响明显。不同充填度模袋砂破坏机理不尽相同，充填度较大时，模袋砂很快进入张拉变形而破坏，破坏主要发生在模袋缝制接口等相对薄弱处；随着充填度的减小，模袋砂破坏主要由砂应变局部化所致，表现为接触界面处的渐进破坏，因破坏不易发现而对实际工程较为不利。与试验结果对比表明，完善后的理论计算方法可用于模袋砂整体张拉破坏时抗压强度预测

Compressive strength and influential factors of geotextile bag with sand

The compression tests were conducted on geotextile bags with sand of different sizes,different volume and different compactness to explore influences of friction,compactness and size on the compressive strength and failure mode.The calculation formula of compressive strength considering the interface friction and compactness was proposed based on the existing theoretical research results.The results indicate that the compressive strength of a single sample is greater than that of many samples,so the existing studies on the single geotextile bag with sand have some deficiencies.The compressive strength of geotextile bag with sand decreases with the increase of the compactness.The sizes have a little effect on the mechanical and deformation and have significant effects on the ultimate bearing capacity.The failure mechanism of geotextile bag with sand is different under different compactness:it quickly produces the tensile deformation and failure when the compactness is large,and failure occurs mainly in the sewing interface which is relatively weak.With the decrease of the compactness,the geotextile bags show progressive failure caused by the strain localization,which is unfavorable because the failure is uneasy to find in the practical engineering.The comparison with the test results indicates that the theoretical calculation method can be used to predict the compressive strength when the tensile failure.