带初始损伤岩石在温度、化学、围压作用下力学性能的研究

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摘要

本文主要通过单轴压缩试验，对不同初始损伤程度的白砂岩在经过高温、低

温冻融、化学溶蚀作用后的物理力学性质进行研究，并通过三轴压缩试验，对带

初始损伤白砂岩的物理力学性质进行研究，得到了不同条件下白砂岩的力学性能

的变化规律，分析了高温、化学溶蚀下白砂岩的损伤机制，建立了低温冻融下白

砂岩的本构模型，求出了白砂岩的内摩擦角及粘聚力。

岩石材料是一种复杂的天然介质，其内部存在着大量的地质缺陷。在实际工

程中，岩石材料往往都是带着初始损伤工作的，这些初始损伤的存在，使得岩石

的宏观刚度和强度都有所下降。各种工程事故的发生，也往往与之相关。在影响

岩石破坏的因素中，温度、化学的影响十分显著；地基岩体一般都是处于三维受

力状态，进行三轴试验更能体现自然界岩石的力学特性，故本文主要从以下四个

方面开展研究：

（1）通过不同初始损伤白砂岩不同高温后的单轴压缩试验，从质量、应力、

应变、应力-应变曲线、相对杨氏模量、相对纵波波速、微观结构等方面探讨了初

始损伤及温度对白砂岩物理力学性能的影响。试验表明：施加初始损伤后，白砂

岩试块的相对杨氏模量、相对纵波波速及峰值应力都有所变小；高温后，白砂岩

的峰值应力在 600℃时达到最大值，600℃之后随温度的增加而减小；白砂岩的杨

氏模量在 1200℃时骤降到原本杨氏模量的一半，且打开炉门时试块已变通红，试

块破坏后的微观图上颗粒比其他组要小，由此可判断 1200℃时白砂岩内部已发生

了质变。并从高温下白砂岩试块的化学反应进行了高温作用下白砂岩的损伤机理

分析。

（2）通过不同初始损伤白砂岩冻融循环后的单轴压缩试验，从应力、应变、

应力-应变曲线、相对杨氏模量、相对纵波波速、微观结构等方面探讨了初始损伤

及低温冻融对白砂岩物理力学性能的影响。试验表明：冻融循环后，白砂岩的相

对杨氏模量、相对纵波波速、峰值应力都有所变小，说明低温冻融对试块造成了

一定的损伤；冻融循环后，试块的应变有所变大，破坏后断口处的颗粒也比未冻

融试块的要小，并由推广后的应变等价原理推导出了白砂岩冻融作用下的本构方

程。

（3）通过不同初始损伤白砂岩酸溶蚀后的的单轴压缩试验，从质量、应力、

应变、应力-应变曲线、相对杨氏模量、相对纵波波速、微观结构等方面探讨了初

始损伤及酸溶蚀对白砂岩物理力学性能的影响。试验表明：在经过酸溶蚀后，白

砂岩试块的质量、相对杨氏模量、相对纵波波速、峰值应力都变小，破坏后试块

的断口处颗粒的大小无明显变化，说明酸与试块的化学反应只在试块的表面进行。

并由白砂岩内部的化学成分及与酸的化学反应分析了酸溶蚀下白砂岩的损伤机理。

（4）通过带初始损伤白砂岩在不同等围压下的三轴压缩试验，分析了不同围

压下的应力应变、破坏模式及微观变化。试验表明：白砂岩试块的峰值应力随着

围压的增大而增大，其值比单轴下的峰值应力有较大增加；在三轴压缩下，白砂

岩试块主要有劈裂破坏、锥形破坏、单剪破坏、双剪或多剪破坏、剪切与竖向劈

裂组合破坏五种破坏模式；破坏后的岩屑颗粒比单轴破坏后的颗粒明显变小且小

于晶体颗粒，说明三轴压缩时产生了较多的穿晶破坏。并画出摩尔应力圆，求得

试块的摩擦角为 60°，粘聚力为 8MPa 左右。

本文根据试验研究成果，总结了温度变化、化学溶蚀、低温冻融及围压等因

素对岩石的力学性能损伤和破坏的规律。而这一问题的研究对解决目前岩土工程

的许多现实问题及文物保护等有重要指导作用。

关键词：白砂岩初始损伤微观三轴温度化学溶蚀

ABSTACT

In this article, physical - mechanical properties of white sandstone with

various degree of initial damage after high temperature, freezing-thawing, chemical

corrosion were studied through uniaxial compression test, and

physical - mechanical properties of white sandstone with initial damage were discussed

through triaxial compression test. The change rule of physical and mechanical

properties of white sandstone were gained under different test conditions. The damage

mechanism of white sandstone were analyzed after high temperature and chemical

corrosion. The constitutive model of white sandstone after freezing-thawing was

established. The angle of internal friction and the cohesive force of white sandstone

were calculated.

Rock is a kind of complex natural medium, there are a lot of geological defects

within it. In practical engineering, the rock material always works with initial damage；

and the existence of initial damage influences the macro stiffness so that strength of the

rock drops. Various engineering accidents are usually associated with it. Due to these

factors affecting the breaking of rock, the effects of temperature and chemical corrosion

are very significant. Foundation rock masses are general in the three-dimensional

stress state, then the triaxial tests can reflect the mechanics characteristics of rock better

naturally compared to uniaxial tests, so this paper mainly studied the following four

aspects:

(1) Through uniaxial compression test of the white sandstone with different

initial damage after different high temperature, the effects of initial damage and

temperatures to the physical - mechanical properties of white sandstone were

discussed in terms of quality, stress, strain, stress and strain curve, relative Young's

modulus, relative compressional wave velocity, and microstructure. The experimental

results showed that: with the initial damage, the relative Young's modulus, the relative

vertical wave and the peak stress of the white sandstone block bacame smaller; after

high temperature, the peak stress of the white sandstone reached the highest point at

600 ℃, then decreased with the increasing of temperature. The Young's modulus of

white sandstone plunged into half of the original Young's modulus at 1200 ℃. The

surface of samples became red when the muffle furnace was opened, and the particles

were smaller than other groups under the microscope , and it could be estimated that

the internal qualitative of white sandstone had changed at 1200 ℃. The

damage mechanism of white sandstone after high temperature was analyzed from the

aspect of chemical reaction.

(2) Through uniaxial compression test of the white sandstone with different initial

damage after freezing-thawing, the effects of initial damage and freezing- thawing to

the mechanical properties of white sandstone were discussed in terms of stress, strain,

stress and strain curve, relative Young's modulus, relative compressional wave velocity

and the microstructure. The experimental results showed that: the relative Young's

modulus, the relative vertical wave and the peak stress of the white sandstone block

bacame smaller after the freezing-thawing so it could be known that the

freezing-thawing had caused damage to the specimens. The strain increased and the

particles were smaller compared to the ones which were not under freezing-thawing.

The constitutive model of white sandstone after freezing and thawing was established

based on the strain equivalent principle.

(3) Through uniaxial compression test of the white sandstone with different initial

damage after chemical corrosion, the effects of initial damage and acid corrosion to the

mechanical properties of white sandstone were discussed in terms of quality, stress,

strain, stress and strain curve, relative Young's modulus, relative compressional wave

velocity and the microstructure. The experimental results showed that: the quality, the

relative Young's modulus, the relative vertical wave and the peak stress of the white

sandstone block bacame smaller after acid corrosion, and the particles on the microgram

did not change dramatically so it could be estimated that the chemical reaction only

occured on the surface of the samples. The damage mechanism of white sandstone after

chemical corrosion was analyzed in terms of the chemical composition inside of white

sandstone and chemical reaction.

(4) Through triaxial compression test of the white sandstone with initial damage,

the stress and strain, failure mode, and micro change were studied under different

confining pressure. The experimental results showed that: the peak stress of the white

sandstone increased with the increasing of confining pressure，and much larger than that

in uniaxial compression. There were five kinds of failure mode: splitting failure, cone

failure, single shear failure, double or more shear failure, combination of splitting and

shear failure. The debris particles were significantly smaller than that caused by

uniaxial compression, and smaller than the crystal particles, it showed that greater

amount of transgranular damage were produced when in triaxial compression. The

Moore stress circle were drawed and the angle of internal friction and cohesive force of

white sandstone were solved out in this paper.

In this paper, the law of damage and destruction to rock in factors of temperature

changes, chemical corrosion, freezing-thawing and confining pressure was summarized

based on the experimental results, and the study t on these problems can become a

guiding role when these are used to solve practical problems and conservation projects..

Keywords: white sandstone, initial damage, microscopic, triaxial,

temperature, chemical corrosion

中文摘要

ABSTRACT

第一章绪论 ................................................................................................................ 1

1.1 研究背景和意义 ................................................................................................ 1

1.2 国内外研究概况 ................................................................................................ 2

1.2.1 岩石损伤力学理论研究概况 .................................................................. 2

1.2.2 岩石高温效应研究概况 .......................................................................... 5

1.2.3 岩石低温冻融研究概况 .......................................................................... 6

1.2.4 岩石化学效应研究概况 .......................................................................... 7

1.2.5 岩石三轴试验及理论研究概况 .............................................................. 7

1.3 本文主要工作 .................................................................................................... 8

第二章不同初始损伤白砂岩高温后力学性能研究 .............................................. 10

2.1 引言 .................................................................................................................. 10

2.2 试验概况 .......................................................................................................... 10

2.2.1 试样制备 ................................................................................................ 10

2.2.2 试验设备和试验方法 ............................................................................ 10

2.3 试验结果及分析 .............................................................................................. 12

2.3.1 试验现象及表观形态 ............................................................................ 12

2.3.2 相对杨氏模量 ........................................................................................ 13

2.3.3 质量损失率 ............................................................................................ 15

2.3.4 峰值应力 ................................................................................................ 16

2.3.5 应力-应变曲线 ....................................................................................... 17

2.3.6 轴向峰值应变 ........................................................................................ 19

2.3.7 纵波波速 ................................................................................................ 20

2.3.8 微观分析 ................................................................................................ 21

2.4 高温作用下白砂岩的损伤机理分析 .............................................................. 23

2.5 本章小结 .......................................................................................................... 24

第三章不同初始损伤白砂岩冻融循环后力学性能研究 ...................................... 26

3.1 引言 .................................................................................................................. 26

3.2 试验概况 .......................................................................................................... 26

3.2.1 试样制备 ................................................................................................ 26

3.2.2 试验设备和试验方法 ............................................................................ 26

3.3 试验结果及分析 .............................................................................................. 27

3.3.1 相对纵波波速 ........................................................................................ 27

3.3.2 峰值应力 ................................................................................................ 28

3.3.3 应力-应变曲线 ....................................................................................... 29

3.3.4 轴向峰值应变 ........................................................................................ 30

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摘要：

摘要本文主要通过单轴压缩试验，对不同初始损伤程度的白砂岩在经过高温、低温冻融、化学溶蚀作用后的物理力学性质进行研究，并通过三轴压缩试验，对带初始损伤白砂岩的物理力学性质进行研究，得到了不同条件下白砂岩的力学性能的变化规律，分析了高温、化学溶蚀下白砂岩的损伤机制，建立了低温冻融下白砂岩的本构模型，求出了白砂岩的内摩擦角及粘聚力。岩石材料是一种复杂的天然介质，其内部存在着大量的地质缺陷。在实际工程中，岩石材料往往都是带着初始损伤工作的，这些初始损伤的存在，使得岩石的宏观刚度和强度都有所下降。各种工程事故的发生，也往往与之相关。在影响岩石破坏的因素中，温度、化学的影响十分显著；地基岩体一般都是处于三...

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