Studies on the Behavior of Single and Group of Geosynthetic Encased Stone Columns
Studies on the Behavior of Single and Group of Geosynthetic Encased Stone Columns
复制标题
DOI：
10.1061/(asce)gt.1943-5606.0000187
复制
发表时间：
2010-01-01
影响因子：
3.9
通讯作者：
Rajagopal, K.
中科院分区：
文献类型：
--
作者：
Murugesan, S.;Rajagopal, K.
石柱（或颗粒桩）越来越多地被用作地面加固元件，用于支撑各种结构，包括建筑物和柔性结构。石柱的承载能力来自周围土壤的限制。在非常松软的土壤中，这种横向限制可能不够充分，并且石柱本身的形成可能值得怀疑。用合适的土工合成材料包裹单个石柱是提高石柱性能的理想形式之一。这种土工合成材料的包裹使石柱更加坚硬。此外，包裹可以防止石头横向挤压到周围的粘土中，反之亦然，保留石柱的排水功能和骨料的摩擦特性。尽管有许多优点，但土工合成材料包裹石柱的行为和机制尚未完全了解。本文通过在大型试验池中受控条件下制备的粘土床中安装的石柱进行室内模型试验，研究了围护石柱单独承载能力的定性和定量提高。负载测试是在带有或不带有外壳的单个石柱以及一组石柱上进行的。使用不同的土工合成材料对石柱的包裹进行了测试。负载测试的结果表明，由于包裹，石柱的负载能力明显提高。轴向承载能力的增加很大程度上取决于外壳的模量和石柱的直径。测试中还测量了由于包裹而导致石柱上应力集中的增加。测试结果用于制定针对给定载荷和沉降的土工合成材料外壳设计的设计指南。
The stone columns (or granular piles) are increasingly being used as ground reinforcement elements for supporting a wide variety of structures including buildings and flexible structures. The stone columns derive their load capacity from the confinement offered by the surrounding soil. In very soft soils this lateral confinement may not be adequate and the formation of the stone column itself may be doubtful. Wrapping the individual stone columns with suitable geosynthetic is one of the ideal forms of improving the performance of stone columns. This type of encasement by geosynthetic makes the stone columns stiffer and stronger. In addition, encasement prevents the lateral squeezing of stones in to the surrounding clay soil and vice versa, preserves drainage function of the stone column and frictional properties of the aggregates. In spite of many advantages, the behavior and the mechanism of the geosynthetic encased stone columns is not thoroughly understood. This paper investigates the qualitative and quantitative improvement of individual load capacity of stone column by encasement through laboratory model tests conducted on stone columns installed in clay bed prepared in controlled condition in a large scale testing tank. The load tests were performed on single as well as group of stone columns with and without encasement. Tests were performed with different geosynthetics for the encasement of stone column. The results from the load tests indicated a clear improvement in the load capacity of the stone column due to encasement. The increase in the axial load capacity depends very much upon the modulus of the encasement and the diameter of the stone column. The increase in the stress concentration on the stone columns due to encasement was also measured in the tests. The results from the tests were used to develop the design guidelines for the design of geosynthetic encasement for the given load and settlement.