基于扩孔理论的挤密砂桩复合地基桩土应力比计算方法
发布时间：2018-09-03 13:29
【摘要】：基于圆孔扩孔理论,考虑挤密砂桩挤密过程中砂桩本身的挤密体积变化,建立了砂桩桩身压缩模量的计算方法。采用Mohr-Coulomb屈服准则计算桩周土屈服区范围,同时结合桩间土的e-p曲线压缩理论,提出了基于扩孔理论的桩周土平均压缩模量计算公式,从而提出了考虑埋深影响的分层桩土应力比计算方法。结合越南河内-海防高速公路实际工程进行了计算分析,随着套管直径增大(0.5~0.6 m),挤密砂桩和桩周土的压缩模量都变小,但平均桩土应力比增大,从2.56增大至2.72,这符合《复合地基技术规范》中对于无实测资料时,桩间土强度低时桩土应力比取大值,桩间土强度高时取小值的规定。桩土应力比理论计算结果处于规范建议取值2~3之间。说明理论方法合理可靠,从而提高了挤密砂桩设计的科学性。
[Abstract]:Based on the theory of circular hole expansion and considering the change of compaction volume of sand pile during compaction, the calculation method of compression modulus of sand pile body is established. The Mohr-Coulomb yield criterion is used to calculate the yield zone of the soil around the pile, and combining with the e-p curve compression theory of the soil between piles, a formula for calculating the average compressive modulus of the soil around the pile based on the theory of hole expansion is proposed. A method for calculating the stress ratio of layered pile to soil considering the influence of buried depth is put forward. Combined with the actual project of Hanne-Haiphong Expressway in Vietnam, calculation and analysis are made. With the increase of casing diameter (0.5 ~ 0.6 m), the compression modulus of compacted sand pile and surrounding soil becomes smaller, but the average pile-soil stress ratio increases. The increase from 2.56 to 2.72 is in accordance with the stipulation that the stress ratio of pile to soil is large when the strength of soil between piles is low and the strength of soil between piles is small when there is no measured data in Technical Specification for Composite Foundation. The theoretical calculation results of pile-soil stress ratio are between 2 ~ 3 and 2 ~ 3 recommended in the code. The theoretical method is reasonable and reliable, and the design of compacted sand pile is more scientific.
【作者单位】： 河海大学岩土力学与堤坝工程教育部重点实验室;河海大学土木与交通学院;
【基金】：江苏省自然科学基金面上项目(No.BK20141419) 国家博士后基金(No.2015M571656) 浙江省交通运输厅科技计划重点项目(No.2015J09) 中央高校基本科研业务费专项资金(No.2015B25914) 广东省交通运输厅科技支撑项目(No.201302023)~~
【分类号】：TU432;TU473.1
本文编号：2220108
[Abstract]:Based on the theory of circular hole expansion and considering the change of compaction volume of sand pile during compaction, the calculation method of compression modulus of sand pile body is established. The Mohr-Coulomb yield criterion is used to calculate the yield zone of the soil around the pile, and combining with the e-p curve compression theory of the soil between piles, a formula for calculating the average compressive modulus of the soil around the pile based on the theory of hole expansion is proposed. A method for calculating the stress ratio of layered pile to soil considering the influence of buried depth is put forward. Combined with the actual project of Hanne-Haiphong Expressway in Vietnam, calculation and analysis are made. With the increase of casing diameter (0.5 ~ 0.6 m), the compression modulus of compacted sand pile and surrounding soil becomes smaller, but the average pile-soil stress ratio increases. The increase from 2.56 to 2.72 is in accordance with the stipulation that the stress ratio of pile to soil is large when the strength of soil between piles is low and the strength of soil between piles is small when there is no measured data in Technical Specification for Composite Foundation. The theoretical calculation results of pile-soil stress ratio are between 2 ~ 3 and 2 ~ 3 recommended in the code. The theoretical method is reasonable and reliable, and the design of compacted sand pile is more scientific.
【作者单位】： 河海大学岩土力学与堤坝工程教育部重点实验室;河海大学土木与交通学院;
【基金】：江苏省自然科学基金面上项目(No.BK20141419) 国家博士后基金(No.2015M571656) 浙江省交通运输厅科技计划重点项目(No.2015J09) 中央高校基本科研业务费专项资金(No.2015B25914) 广东省交通运输厅科技支撑项目(No.201302023)~~
【分类号】：TU432;TU473.1
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，本文编号：2220108
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