基于弹性薄膜理论的台背加筋间距计算方法研究

Research on Calculation Method of Abutment Reinforcement Spacing Based on Elastic Film Theory

采用土工合成材料防治路桥过渡段不均匀沉降时,《公路土工合成材料应用技术规范》建议在桥台附近可以采用反包或者锚固的方式对土工合成材料进行处理,但是规范仅给出一种铺设间隔计算公式,未明确提出间隔计算公式适用于反包还是锚固处理方式,鉴于采用反包和锚固两种处理方式时土工合成材料的边界条件存在差异,有必要对反包和锚固情况下的铺设间距计算进一步研究.以弹性薄膜理论为基础,建立土工合成材料在土体中加筋的受力模型,以反包和锚固两个边界条件,推导得到两种情况下土工合成材料铺设间距计算方法.经在湖北潜江至石首高速公路试验段应用,采用该法计算得到的土工合成材料铺设间距合理,对路桥过渡段不均匀沉降处治效果显著.

When geosynthetic materials are used to prevent uneven settlement of road-bridge transition section,the Technical Specification for Application of Geosynthetic Materials in Highway recommends that geosynthetic materials can be treated by reverse-packing or anchoring near the abutment.However,the specification only provides a calculation formula for laying interval,and does not explicitly propose whether the interval calculation formula is applicable to reverse-packing or anchoring treatment.In view of the difference in the boundary conditions of geosynthetics when the two treatment methods are used,it is necessary to further study the calculation of laying distance under the conditions of reverse-packing and anchoring.Based on the theory of elastic membrane,this paper established the stress model of geosynthetic reinforcement in soil,and deduced the calculation method of geosynthetic paving distance under two conditions with the two boundary conditions of reverse-packing and anchoring.After being applied to the test section of Qianjiang-Shishou Expressway in Hubei Province,the geosynthetic materials calculated by this method have reasonable laying spacing and have remarkable treatment effect on uneven settlement of road-bridge transition section.