滇中红层泥岩剪切蠕变特性及其本构模型

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国家科技期刊平台
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中文摘要：为保障滇中红层泥岩所在区域隧洞工程的施工及长期运营安全，本文以"滇中引水工程"狮子山隧洞段的红层泥岩为研究对象，首先，采用分级加载剪切蠕变试验方法，研究其蠕变特性;其次，基于非线性流变力学理论，分别构建了触发式非定常加速元件、非线性弹性元件及复合型黏性元件;第三，通过各元件的合理组合，建立了滇中红层泥岩的非线性、非定常蠕变模型;最后，对所建模型进行参数估计，与试验结果进行对比，验证理论模型的适用性。研究结果表明:在较低应力状态下，岩样主要表现为衰减蠕变，其中蠕变变形在总变形中的占比可达85%;而在较高应力状态下，岩样发生从衰减蠕变、等速蠕变直至加速蠕变破坏的全过程蠕变，其中蠕变变形在总变形中的占比达87%。剪应力对岩样蠕变变形具有显著影响，剪应力越高，衰减蠕变达到稳定状态所需的时间越长，蠕变变形在总变形中的占比越高。在全过程蠕变中，岩样的蠕变变形以稳态蠕变为主，其蠕变时间占总蠕变时间的80%，蠕变量占总蠕变量的51%。该蠕变模型既能完整地描述岩样从衰减到等速直至加速蠕变的全过程，同时又能克服传统模型参数取值随应力而不断变化的问题，通过一组参数就可以描述岩样在各应力状态下的蠕变变形特性。理论模型得到的结果与试验结果吻合较好，说明所建模型对于滇中红层泥岩具有较好的适用性。

外文标题：Shear creep characteristics and constitutive model of red-bed mud-stone in Central Yunnan

外文摘要：To ensure the construction safety and long-term operation of the tunnel project in the area where the red-layered mudstone was located,the red layer mudstone in the Shizishan tunnel section of the"Central Yunnan Water Diversion Project"was taken as the research object.Firstly,the creep characteristics of the tunnel were studied by using the shear creep test method under graded loading.Secondly,trigger-type non-steady-state acceleration elements,nonlinear elastic elements and composite viscous elements were developed by utilizing nonlinear viscoelastic theory.Thirdly,these models were effectively integrated to establish a nonlinear,non-steady-state creep model for red-layered mudstone.Finally,parameters of the model were estimated and compared with the experimental results to verify the applicability of the theoretical model.The results show that at lower stresses,the rock samples mainly exhibit decay creep,in which creep deformation accounts for 85%of the total deformation.At higher stresses,the rock samples will undergo the whole process of creep from decay creep,steady state creep to accelerated creep,in which creep deformation accounts for 87%of the total deformation.The shear stress has a significant effect on the creep deformation of rock samples.The higher the shear stress,the longer the time required for decay creep to reach the steady state,and the higher the proportion of creep deformation in the total deformation.In the whole process of creep,the creep deformation of rock samples is dominated by steady-state creep,whose creep time accounts for 80%of the total creep time,and creep deformation accounts for 51%of the total creep deformation.The model can completely describe the whole process of creep from decay to steady state and to accelerated creep of the rock sample.At the same time,it overcomes the problem that the parameter values of the traditional model keep changing with the stress level.The creep deformation characteristics of the rock sample in each stress state can be described by one set of parameters.The results obtained from the theoretical model are in good agreement with those of the experiment,indicating that the proposed model has good applicability to the red-layered mudstone in Central Yunnan.

外文关键词：

red-bed mudstone in Central Yunnancreep characteristicsunsteady acceleration elementnonlinear creep modelparameter identification

作者：

李宁、张茂建、张慧莉、徐诚、汪波

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作者单位：

上海理工大学环境与建筑学院,上海,200093

同济大学岩土及地下工程教育部重点实验室,上海,200092

上海城建城市运营(集团)有限公司,上海,200023

关键词：

滇中红层泥岩蠕变特性非定常加速元件非线性蠕变模型参数辨识

基金：

国家自然科学基金资助项目国家自然科学基金资助项目上海市自然科学基金资助项目

项目编号：

40872179U176511016ZR1423300

出版年：

2024

DOI：

10.11817/j.issn.1672-7207.2024.09.024

中南大学学报(自然科学版)

中南大学

中南大学学报(自然科学版)

CSTPCD北大核心

影响因子：0.938

ISSN：1672-7207

年,卷(期)：2024.55(9)