摘要
通过铁路路基室内试验和现场填筑试验,对比研究了复合土工膜、橡胶合成纤维土工布两种材料的基本力学性能和在不同防排水层构造中的施工损伤,总结了基床防排水层的施工工艺,并探讨了基床防排水层构造优化。结果表明:橡胶合成纤维土工布具有较低的伸长率、较高的强度,其抗拉断裂强度和顶破强力约为复合土工膜的5倍和3倍,其施工损伤系数明显小于复合土工膜,具有较强的抗施工损伤性能。薄层砂垫层宜采用人工摊铺或人工粗平与机械平整相结合的施工方法。砂垫层厚度在0~10 cm时,施工对两种材料的力学性能影响较小,但不铺设砂垫层对材料的水力学性能影响较大。仅考虑施工损伤因素时,可在提高土工合成材料强度、优化填料级配及其施工工艺的条件下,针对性优化基床防排水层的砂垫层厚度。
Through the indoor test and field filling test of railway subgrade,the basic mechanical properties and construction damage of composite geomembrane and rubber synthetic fiber geotextile in different waterproof and drainage layer structures were compared and studied.The construction technology of waterproof and drainage layer of subgrade bed was summarized,and the structure optimization of waterproof and drainage layer of subgrade bed was discussed.The results show that the rubber synthetic fiber geotextile has lower elongation and higher strength,its tensile breaking strength and bursting strength are about 5 and 3 times of that of the composite geomembrane,respectively.Its construction damage coefficient is significantly smaller than that of the composite geomembrane,which has strong construction damage resistance.The construction method of manual paving or manual roughing combined with mechanical leveling shall be adopted for the thin sand cushion.When the thickness of the sand cushion is 0 ~ 10 cm,the construction has a small impact on the mechanical properties of the two materials,but the hydraulic properties of the materials are greatly affected by not laying the sand cushion.When only construction damage factors are considered,the sand cushion thickness of the waterproof and drainage layer of the subgrade bed can be targeted optimized under the conditions of improving the strength of geosynthetics,optimizing the filler gradation and construction technology.
作者
王亚飞
李立
彭锴
WANG Yafei;LI Li;PENG Kai(China Railway Siyuan Survey and Design Group Co.,Ltd,Wuhan 430063,China)
出处
《铁道建筑》
北大核心
2023年第1期122-126,共5页
Railway Engineering
基金
中铁第四勘察设计院集团有限公司科技研究开发计划课题(2019K028)。
关键词
铁路路基
基床防排水层
现场试验
复合土工膜
橡胶合成纤维土工布
施工损伤
railway subgrade
waterproof and drainage layer of subgrade bed
field test
composite geomembrane
rubber synthetic fiber geotextile
construction damage
