【作者】 马立；

【导师】 马石城；

【作者基本信息】 湘潭大学 ， 结构工程， 2011， 硕士

【摘要】 土工格栅具有优良的材料性能,将其加入路基土中后,土体强度和刚度得到提高,可有效减少路基不均匀沉降和总体沉降、限制侧向位移、防止桥台跳车等。相比一般路基处理方法,土工格栅加筋路堤具有造价低廉、技术简单、施工工期短、对各类地基实用性较好等优点,因此在工程上得到了更加广泛的运用。目前,对土工格栅加筋路堤承载力的研究水平远远高于沉降问题的研究。一些学者对土工格栅加筋土沉降问题进行了模型试验和有限元分析,取得了一些成果,但仍缺乏较为成熟的可直接用于工程计算的理论方法。鉴如此,本文基于渐近均匀化理论提出了一种新的用于计算水平向增强体(土工格栅)复合地基沉降的理论方法。主要研究内容如下:(1)针对土工格栅加筋土具有周期性结构的特点,提出了用于计算加筋路堤沉降的渐近均匀化方法,总结了基于渐近均匀化理论计算宏观有效弹性常数的步骤。(2)以工程实例为原型,利用渐近均匀化程序计算得到的加筋路堤等效模量,采用《公路路基设计规范》沉降计算公式(分层总和法),求得了加筋路堤总体沉降量,与工程实测值进行了对比,证明了其可行性。(3)结合模型试验及工程实例,将渐近均匀化方法求得的复合变形模量计算值与载荷试验的实测值对比表明,渐近均匀化方法计算成果是合理的。(4)结合工程实例,运用渐近均匀化方法分析了土工格栅加筋路堤沉降变形影响因素,结果表明:加筋层间距、土工格栅模量、网格尺寸为一合理值时,加筋效果较好,且土工格栅对于软土加筋效果较明显。通过对工程实例的验算,基于渐近均匀化理论的沉降计算值比实测值约偏大9%,表明该理论用于土工格栅加筋路堤沉降计算是有效的。更多还原

【Abstract】 Geogrid has excellent material properties. When be added to the subgrade, the soil strength and stiffness is improved. Geogrid can effectively reduce the differential settlement and the overall settlement, limite lateral displacement,prevente the abutment jumping. Compared to general treatment methods, geogrid reinforced embankment has lower cost, more simple technology, shorter construction period, more applicable to all types of foundation,so has been more widely used.Currently, the bearing capacity of geogrid reinforced embankment is much higher than the level of settlement research. A lot of scholars achieved some result by way of model test and finite element analysis, but still lack mature theoretical methods which can be directly used for engineering calculations.For this situation, This paper proposes a new method of calculating settlement which is used to calculate horizontal reinforcement (geogrid) composite foundation based on the asymptotic homogenization theory.this paper completed the major work as follows: (1)According to the reinforced geogrid is cyclical, the author puts forward the asymptotic homogenization method of the settlement calculation of the reinforced embankment, and summarizes steps to calculate the effective elastic constants. (2) Based on the actual project, we calculate geogrid reinforced embankment equivalent modulus by using the asymptotic uniformity program;then calculate the settlement of embankment with geogrids by delamination summation-method ; at last, we compare the settlement calculated with measured settlement.The result proved that the method is feasibility.(3) Combined with model test and engineering example, compare the elastic modulus calculated based on asymptotic homogenization theory with measured settlemen of load ,and proved its viability.(4)Analyze deformation of geogrid reinforced embankment settlement factors based on asymptotic homogenization theory.Checking through the engineering examples, calculated value of settlement based on asymptotic homogenization theory is larger than the measured value of about 9%.So it shows that the method of settlement calculation for the geogrid reinforced embankment is rational.更多还原