基础理论与实验研究

考虑孔压积累-消散耦合的等效有限元方法

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  • 1. 同济大学 地下建筑与工程系,上海 200092;2. 同济大学 岩土及地下工程教育部重点试验室,上海 2000923
钱建固,男,1972年生,博士,教授,博士生导师,主要从事地下工程及岩土力学方面的研究与教学工作

收稿日期: 2015-03-10

  网络出版日期: 2018-06-14

基金资助

国家自然科学基金(No.41272291,No.51238009)

Equivalent finite element method considering coupling pore pressure accumulation and dissipation

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  • 1. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China

Received date: 2015-03-10

  Online published: 2018-06-14

摘要

交通荷载往复作用下饱和软土路基会发生显著的工后沉降,并引起不均匀沉降。采用基于室内循环三轴或空心圆柱扭转试验建立的经验显式模型与等效有限元相结合方式,在预测路基长期沉降方面取得了较好的效果。然而,其采用的瞬时积累、逐步消散的孔压模型与实际工程中孔压积累与消散同时进行有着明显的差异。忽略这种差异将会使得计算结果低于实际值。采用能反映自然排水条件下震动孔压长消规律的解析公式,对以上的不足作出改进,并用改进的孔压模型计算了上海浦东国际机场第一跑道的长期运营沉降。分析表明,与瞬时积累、逐步消散的孔压模型相比,考虑孔压积累与消散耦合效应的孔压模型,计算结果更接近实测资料。

本文引用格式

钱建固 ,林志果 ,马 霄 , . 考虑孔压积累-消散耦合的等效有限元方法[J]. 岩土力学, 2015 , 36(S1) : 125 -130 . DOI: 10.16285/j.rsm.2015.S1.021

Abstract

Significant post-construction settlement will be induced under the action of cyclic traffic load in saturated soft soil subgrade and it is also responsible for most differential settlement. To predict the long-term settlement of subgrade, experiential explicit constitutive models based on cyclic triaxial test or hollow cylinder test is combined with equivalent finite element method and it has achieved good effect. The pore pressure model used above is accumulating instantly and dissipating gradually, but the true pore pressure model is accumulation and dissipation proceeding simultaneously. This difference between them will make the settlement calculated by older pore water pressure model be smaller than normal. This paper improves the pore pressure model used currently by applying an analytical expression which can reflect the rules of pore pressure accumulation and dissipation under condition of vibration and natural drainage; and the improved model is used to predict the long-term settlement of the first runway subgrade in Shanghai Pudong International Airport. Compared with the current model’s result, the result based on improved model is closer to the measured actual data.
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