土工基础

土工基础 ›› 2020, Vol. 34 ›› Issue (2): 204-207.

• 专题论述 • 上一篇    下一篇

温度梯度下红黏土的强度特性变化规律

多会会，胡艳香，李 炀，朱厚影，陈国防   

  1. （东华理工大学  建筑工程学院，南昌 330013）
  • 收稿日期:2019-09-25 修回日期:2019-11-04 出版日期:2020-05-20 发布日期:2020-05-20
  • 作者简介:多会会（1991-），女，硕士研究生，研究方向为建筑与土木工程。
  • 基金资助:
    江西省自然科学基金（20192BAB206045）；国家自然科学基金（41462011）。

Variation of Strength Characteristics of Red Clay under Temperature Gradient

DUO Huihui, HU Yanxiang, LI Yang, ZHU Houying, CHEN Guofang   

  1. (School of Architectural Engineering, East China University of Technology, Nanchang 330013)
  • Received:2019-09-25 Revised:2019-11-04 Online:2020-05-20 Published:2020-05-20

摘要： 采用应变应力控制式直剪仪，研究了红黏土在27~95 ℃五种温度梯度下的强度特性。试验结果表明：强度特性指标参数的温度效应都受到了含水率与干密度的影响，但含水率对强度特性的温度敏感度明显高于干密度；当低于65 ℃时，强度特性与温度正向增长；当温度在50~65 ℃范围内，φ随温度升高而降低，呈红黏土的热软化状态；当高于65 ℃时，φ与温度正比例增长，呈剪切硬化状态。红黏土热硬化和热软化的临界温度在65 ℃处。红黏土热硬化和热软化的临界温度在65 ℃处，对研究地下红黏土强度特性的温度影响有一定参考价值。

关键词: 黏聚力, 内摩擦角, 温度效应, 直剪试验

Abstract: In this paper, the strength characteristics of the red clay under five temperature gradients ranging from 27 to 95 ℃ were studied by a strainstress controlled direct shear apparatus. The test results show that the temperature effect of the strength characteristic parameters is affected by the water content and the dry density, but the temperature sensitivity of the water content sample on the strength characteristic is obviously higher than that of drier density sample with less water content; when the temperature is lower than 65 ℃, the strength characteristic and temperature increase positively; Within the range from 50 to 65 ℃, the φ decreases with the increase of temperature, showing a state of thermal softening of the red clay; when the temperature is higher than 65 ℃, the shear strength increases in proportion to temperature, showing a state of shear hardening. Therefore, the critical temperature of thermal hardening and softening of the red clay is 65 ℃. The critical temperature of thermal hardening and softening of red clay is 65 ℃, which is valuable for the studying of the temperature effect on the strength characteristics of the insitu red clay.

Key words: cohesion, internal friction angle, temperature effect, direct shear test

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