地下水侵蚀、温度变化和初始损伤影响的岩石力学特性研究
摘要
本文主要对地下水侵蚀、温度变化和初始损伤影响的岩石力学特性研究，并
且推导出了关于不同裂缝角度的各应力分量解析式和裂缝尖端处最大剪应力的解
析式。
在实际工程中，考虑到岩石材料自身的组成成分很复杂，内部含有大量的微
观和宏观裂缝，而且常常处在多种恶劣环境下工作，所以分析自然环境对岩石力
学性能的影响很有必要。比如地下污水的侵蚀、严寒地区的冻融循环作用和高温
环境下的热胀作用都严重的影响着岩石的力学性能，再加上自身含有的初始损伤
和内部无数多的微观和宏观裂缝，这些都是对岩石耐久性的严峻考验。考虑到以
上因素，所以本文主要就以下四个方面的内容进行了研究：
(1)本文通过用白水泥制作带0°、15°、30°、45°、60°和90°裂缝的试块来模拟
实际岩石材料的裂缝。并且通过对不同裂缝角度的试块进行单轴压缩试验，得出
了当裂缝角度在 0°~45°变化时，随着岩石试块裂缝角度的增大，试块的破坏接近
于剪切破坏，试块的强度随裂缝角度增大而减小。当倾角60°~90°变化时，随着岩
石试块裂缝角度的增大，有少数试块出现拉张破坏。最终得出带45°角裂缝的岩石
强度最小，所以实际工程中应特别注意45°的岩石裂缝。在此基础上应用平面应力
问题的逆解法推导出岩石试块不同的裂缝角度的应力分量和最大剪应力解析式，
为今后实际工程提供了理论基础。最后通过有限元软件ANSYS 分析了带0°、15°、
30°、45°、60°和90°裂缝的岩石试块在轴向压力作用下的剪应力和位移大小。
(2)在实际工程中，岩石大多是含初始损伤的，分析含初始损伤岩石的力学性
能有重要的工程意义。本文预先统计岩石试块的初始抗压强度，然后根据其抗压
强度给岩石试块施加压力。分别施加了极限抗压强度的10%、30%、50%、70%、
80%、90%，以形成不同的初始损伤。然后通过低温冻融试验和单轴压缩试验，将
岩石在传统循环荷载作用后的损伤与低温冻融损伤进行比较，得出这两种损伤的
异同点，建立了岩石材料在不同环境条件下的损伤表达式，研究了初始损伤对岩
石冻融的影响，对今后估测含初始损伤岩石的冻融寿命有一定参考价值。
(3)对于高放射性核废料的地下贮藏和遭受突发性高温（如火灾）作用后的岩
石性质，人们还需要掌握不同高温、高压下及经历不同高温后的岩石物理力学变
化，以便准确解决实际工程中岩石的力学性能。长期以来国内外学者针对岩石的
低温冻融和高温高压下的基本物理力学参数的测定和破坏准则及岩石损伤机制等
多方面都做了一定的研究，取得了一定的成果。但是实际工程中的岩石材料经常
会同时受到高温作用和低温冻融破坏，在多种环境作用下的岩石损伤特性更加复
杂和不确定，对岩石的耐久性和稳定性的影响更为严重。所以本文研究多种因素
同时对岩石的影响更为重要。本文对20℃~900℃高温处理后的岩石材料进行冻融
循环试验，得出了高温后岩石的力学性能随温度的升高而劣化，表现为随着受热
温度的升高花岗岩的抗压强度降低，当温度小于300℃时变化不明显，但是当温度
在300℃~400℃和500℃~600℃时岩石的力学性能很不稳定，峰值应力急剧下降，
在实际工程中，岩石处在该温度区间内应特别注意其力学特性。
(4)本文用四种不同浓度的硝酸溶液模拟实际工程中的工业废水，用 400℃高温
处理后的岩石模拟实际工程中的高放射性核废料中的岩石。通过花岗岩在 0%、1%、
3%、5%四种浓度硝酸溶液和高温共同作用的冻融腐蚀循环试验，研究了岩石质量、
峰值应力和峰值应变随酸性溶液浓度变化的规律，发现岩石在多重因素作用下的
冻融循环损伤更为严重。基于Rabtnov 损伤力学的概念，得出损伤变量 D变化曲
线，揭示了花岗岩力学性能劣化与溶液浓度的关系，为今后冻融腐蚀循环条件下
岩石力学性能的研究提供一定的试验数据和理论基础。
本文依据试验研究成果，总结冻融循环、温度变化、初始损伤和裂缝角度等
多种因素对岩石的损伤、变形、耐久性和破坏的规律。这一问题的研究对解决目
前在建的各种岩石工程中出现的许多现实问题有重要指导作用。
关键词：冻融循环 初始损伤 酸性溶液 高温 岩石 裂缝角度
ABSTRACT
The mechanical properties of rock impacted by the factors, such as: erosion by
groundwater, temperature changes and initial damage, have been studied in this paper.
The analytic expression of the stress components and the maximum shear stress at the
crack tip were deduced.
In the actual project, the complex components of rock material are taken into
account, a large number of micro and macro cracks are existed in the rock internal, and
it often works in a variety of harsh environments, so it is necessary to analyze the
influence of the natural environment work to the mechanical properties of the rock. For
example, the mechanical properties of the rock are seriously impacted by the
underground wastewater erosion, the freeze-thaw cycles in cold regions and high
temperature environment, and the durability of rock are severely tested by the initial
injury and numerous micro-macro cracks exist internal. Since the above factors have
been taken into account, the following four aspects are studied in this paper:
(1) The crack of the actual rock material are simulated by using white cement to
made 0°, 15°, 30°, 45°, 60°, 90°these different angles of test block crack in this
paper .The uniaxial compression test of the test blocks in different fracture inclination
are performed, it was shown when the crack angle was change from 0°to 45°, the
destruction of the test block was closer to shear failure with the increase of cracks
angles, the strength of the test blocks decrease with increasing of crack inclination.
When the change of inclination is 60°~ 90°, the destruction of the test block is closer to
tensile failure with the increase of cracks angles. It was shown that the rock strength
was least when the crack inclination was 45°, so in actual project when the crack
inclination was 45 °should be paid special attention. Base on the plane stress inverse
method, the crack angle stress component of the rock test block and the maximum
analytical solution of the shear stress have been derived, a theoretical basis for future
practical engineering have been provided. Finally, with the finite element software-
ANSYS, the shear stress and the displacement of the test block rock when the
inclination were 0 °, 15 °, 30°, 45°, 60°, 90° have been analyzed.
(2) The rock was always initially damaged in the actual project, so it was
necessary to study the mechanical properties of the rock with initial damages. In this
paper, the initial compressive strength of the rock was accounted in advance,then the
pressure containing 10%, 30%, 50%, 70%, 80% and 90% of the ultimate compressive
strength are given to the rock. By the freeze-thaw cycle tests and uniaxial compression
experiments, the damages of the rock in the traditional cyclic loading and after the low
temperature freeze-thaw cycles are compared, the similarities and differences of these
two damages are obtained, the rock damage model was established under different
conditions, the influence of the initial damage on the behavior of risisting freeze-thaw
was analyzed.The result can provide a reference value to the research of the freeze-thaw
durability of the rock with initial damages.
(3) For the rock which in the underground storage environment of highly
radioactive nuclear waste and suffered sudden to high temperature (such as fire), the
physical and mechanical properties change in different high temperature and high
pressure need to be mastered in order to definite the mechanical properties of the rock in
practical engineering accurately. The basic physical and mechanical parameters of the
rock under freeze-thaw cycles and under high temperature and pressure, as well as
failure criteria and damage mechanism of the rock have been studied by domestic and
foreign scholars in long-term, and certain results have been achieved. But in actual
project, the rock material often subjected to high temperature and low temperature
freeze-thaw damage, the rock damage characteristics under a variety of environmental
effects is more complicated and uncertainty, it takes a more serious impact on the
durability and stability of the rock. The rock impacted when a variety of factors work
at the same time have been studied in this paper. The results that the mechanical
properties of the rock deterioration with the heated temperature increased have been
drawn through the test of rock material under freeze-thaw cycles after high temperature
treatment. It is shown that the compressive strength of granite get lower with the heat
temperature increases, it did not change significantly when the temperature is less than
300 ,℃ but the mechanical properties of the rock is very unstable with a sharp decline
in peak stress when the temperature at 300 ~ 400 and 500 ~ 600 ,℃℃℃℃so it should
be paid great attention in actual engineering when the rock expose to these temperature
ranges.
(4) Four different concentrations of nitrate solution were used to simulate industrial
wastewater in the actual project and used 400 degrees high temperature treatment of the
rock to simulation the rock in the high-level radioactive nuclear waste in the actual
project. In this paper, the variation rule of the rock quality ,peak stress and peak strain
under the influence of freeze-thaw cycle at 0%, 1%, 3%, 5% four concentrations of
nitric acid and high temperature was studied by experimental tests. The results showed
that the rock under the action of multiple factors in the freeze-thaw corrosion damage is
more serious。Based on the concept of damage mechanics of Rabtnov, damage variable
D curves could be gotten and the relationship between the degradation of granite’s
mechanical properties and the concentration could be revealed, which provide some
experimental and theoretical basis for the further study of the mechanical properties
under the freeze-thaw cycling conditions.
Based on the experimental research, the damage, deformation, durability and
destruction law of the rock impacted by many factors, such as: freeze-thaw cycles,
temperature changes, the initial damage and cracks angle, have been summarized. An
important guide to solve rock projects problems in recent practical have been provided
by the study of this problem.
Key word: freeze-thaw cycles, initial damage, acidic solution, high
temperature, rocks, crack-angle
目录
中文摘要
ABSTRACT
第一章 绪论............................................................................................................1
1.1 研究背景 .......................................................................................................1
1.2 研究意义.......................................................................................................1
1.3 岩石力学特性的研究内容与国内外研究现状...............................................2
1.4 岩石材料损伤本构模型................................................................................3
1.4.1 损伤力学概述.........................................................................................3
1.4.3 有效应力及应变等效原理......................................................................5
1.4.4 岩石材料损伤本构模型.........................................................................6
1.5 有限元单元法的简介 ....................................................................................7
1.6 研究内容 ........................................................................................................8
第二章 含宏观裂缝岩石材料的力学特性研究 ....................................................12
2.1 引言.............................................................................................................12
2.2 岩石材料的制备...........................................................................................12
2.3 试验过程与结果分析...................................................................................13
2.4 岩石裂缝受力分析.......................................................................................15
2.4.1 平面应力问题.......................................................................................15
2.4.2 应力函数的逆解法...............................................................................17
2.4.2.1 应力函数............................................................................................17
2.4.2.2 逆解法................................................................................................17
2.4.3 裂缝尖端部位的应力分量....................................................................17
2.5 岩石裂缝的有限单元法力学分析...............................................................22
2.5.1 弹性力学平面问题的有限单元法........................................................22
2.5.2 有限元软件ANSYS 的数值分析.........................................................25
2.6 结论.............................................................................................................29
第三章 冻融条件下含初始损伤的花岗岩力学特性研究.....................................31
3.1 引言.............................................................................................................31
3.2 岩石材料的制备..........................................................................................31
3.3 试验过程与结果分析...................................................................................31
3.3.1 试验设备和试验方法 ...........................................................................31
3.3.2 冻融损伤原理分析...............................................................................32
摘要：
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摘要本文主要对地下水侵蚀、温度变化和初始损伤影响的岩石力学特性研究，并且推导出了关于不同裂缝角度的各应力分量解析式和裂缝尖端处最大剪应力的解析式。在实际工程中，考虑到岩石材料自身的组成成分很复杂，内部含有大量的微观和宏观裂缝，而且常常处在多种恶劣环境下工作，所以分析自然环境对岩石力学性能的影响很有必要。比如地下污水的侵蚀、严寒地区的冻融循环作用和高温环境下的热胀作用都严重的影响着岩石的力学性能，再加上自身含有的初始损伤和内部无数多的微观和宏观裂缝，这些都是对岩石耐久性的严峻考验。考虑到以上因素，所以本文主要就以下四个方面的内容进行了研究：(1)本文通过用白水泥制作带0°、15°、30°、45°...
作者：牛悦
分类：高等教育资料
价格：15积分
属性：68 页
大小：1009.4KB
格式：PDF
时间：2024-11-11
