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chapter 3.2.1 Physical Weathering课程教案、知识点、字幕

同学们好 欢迎来到地质学与工程地质课程

这节课呢 我们来学习风化作用中的物理风化

物理风化呢它其实也就是外部营力

使岩石或构成岩石的一些矿物

在原地发生机械破碎的过程

从机制上来讲呢

又可以分为岩石释重或者是卸荷

温度的变化 冻融破坏

以及可溶盐的结晶与潮解四个方面

一般的来讲呢岩石形成之后

受上覆岩层的压力及构造应力的影响

通常处在一个高压的环境中

一旦由于剥蚀 比如说河流的下切

人工开挖等等 导致作用在岩石上的压力降低

也就是说岩石发生释重或者是卸荷

这种作用呢 将引起岩石向临空面发生膨胀变形

如果发展到一定程度将会形成一系列

与临空面近于平行的张开裂隙

从而破坏岩体的完整性

卸荷作用引起的岩石破坏呢

在自然界中经常的遇到

尤其是一些高山峡谷或高地应力区更为明显

比如我国雅砻江上锦屏一级电站坝址区

由于河流下切作用形成了高陡的峡谷地貌

导致两岸岩体卸荷 引起的物理风化深度

可达两百多米

还有澜沧江上的小湾电站坝址区

属于高地应力区

坝基由于人工开挖卸荷

导致岩体产生这种平行于开挖面的板状破裂面

而且在开挖过程中有时可以听到啪啪啪的声音

自然界中温度变化对岩石的破坏作用呢

主要来自于太阳的辐射热

白天在太阳照射下岩石表面的温度首先升高

同时呢由于岩石是热的不良导体

所以热量不能及时地传递到岩石的内部

这样就在岩石的表层和内部产生了一个温度差

也就是形成了一种外热内凉的状态

相应的也就产生了内外差异受热膨胀现象

从而在岩石的表层会形成

与表面近于平行的微破裂

经过一天的太阳照射呢

热量慢慢地传递到岩石的内部

到了晚上由于周围环境温度迅速降低

所以岩石表层的温度首先降低

形成一个外凉内热的一个状态

相应的产生了差异收缩现象

从而在岩石的表层会形成

与岩石表面近于垂直的微破裂

那么这种作用日复一日年复一年

裂隙呢会不断发展增多

导致岩石层层剥落

使岩石形状逐渐趋于圆滑

形成近似的球状的块石

所以这个过程呢就叫做球形风化

在花岗岩山区呢

经常可以看到有球形风化过程

形成这种风化球 岩块非常的圆润

我们知道岩石裂隙中的水呢

结冰后会发生体积的膨胀

并给裂隙两侧的岩石产生一个膨胀力

如果这个膨胀力超过了岩石的强度

是不是会使裂隙逐渐扩大

并产生新的裂隙

而新的裂隙产生及裂隙的扩张

当然又会使更多的水参与进来

从而进一步促进了这种过程的发展

经过这种多次的冻结 融解后

岩石将逐渐被破坏

这个过程呢我们来称为冻融破坏

又叫做冰劈作用

冻融破坏呢 在一些高纬及高寒地区比较明显

比如我国的北方还有青藏高原地区等等

一般来讲因气候引起温度变化所影响的范围内

也就是在近地表几米 几十米的范围内

所以冻融破坏呢 也主要是在地表的浅部范围

比如这是一个岩石冻融破坏形成的一个断面

可以看出在这条线以上岩石基本上

被破坏成大小差不多的一些岩石碎屑

盐类的结晶与潮解作用呢

主要是指岩石中一些裂隙

或孔隙中被含有可溶性盐的水填充

所以蒸发后这些盐类将结晶并产生体积膨胀

这些过程循环往复

最终使岩石发生解体和破碎

所以呢从岩石破坏的力学机理上来讲

这种作用与冰劈作用类似

在北方呢经常可以看到一些古建筑砖墙外侧

出现一些层层的剥落现象

而且表面会可以看到一些白色的盐碱

其实就是这种风化作用产生一种结果

可以说风化作用是外动力地质作用的开始

它为其它的外动力地质作用提供了物质基础

而物理风化呢

又是风化作用中最重要的一种类型

所以通过这节课的学习呢

同学们要重点掌握物理风化作用

它的机理类型及其对人类工程活动一些影响

Geology and Engineering Geology课程列表:

0 Introduction

-0.1 Human Engineering Activities and the Geological Environment

--Chapter 0.1 Human Engineering Activities and the Geological Environment

-0.2 Tasks for Engineering Geology

--Chapter 0.2 Tasks for Engineering Geology

-0 Quiz--Homework

1 The Earth and the Crust

-1.1 Formations and Evolution of the Earth

--Chapter 2.1 Formations and Evolution of the Earth

-1.2 Basic Attributes of the Earth

--Chapter 1.2 Basic Attributes of the Earth

-1.3 Construction of the Geo-sphere and the Geological Processes

--Chapter 1.3 Construction of the Geo-sphere and the Geological Processes

-1 Quiz--Homework

2 Endogenic Geological Process

-2.1 Crustal Movement

--Chapter 2.1 Crustal Movement

-2.2 Magmatism

--Chapter 2.2 Magmatism

-2.3 Metamorphism

--Chapter 2.3 Metamorphism

-2.4 Earthquake

--Chapter 2.4 Earthquake

-2 Quiz--Homework

3 Exogenic Geological Process

-3.1 Introduction

--Chapter 3.1 Introduction

-3.2 Weathering Effects

--chapter 3.2.1 Physical Weathering

--chapter 3.2.2 Chemical and Biological Weathering

--chapter 3.2.3 Weathering Products and Influencing Factors of the Weathering Process

-3.2 Weathering Effects--Homework

-3.3 Geological Effects of the Flowing Surface Water

--chapter 3.3.1 Geologic Process of Temporary Torrents

--chapter 3.3.2.1 River Erosion Effects

--chapter 3.3.2.2 River Transport and Sedimentation Effects

-3.3 Geological Effects of the Flowing Surface Water--Homework

-3.4 Geological Effects of Winds

--Chapter 3.4 Geological Effects of Winds

-3.4 Geological Effects of Winds--Homework

-3.5 Geological Effects of Glaciers

--Chapter 3.5 Geological Effects of Glaciers

-3.5 Geological Effects of Glaciers--Homework

-3 Quiz Easy--Homework

-3 Quiz Enhanced--Homework

4 Minerals and Rocks

-4.1 Minerals

--Chapter 4.1.1 Minerals and Their Morphological Characteristics

--4.1.2 Minerals and Rocks-Mineral Characteristics-Physical and Mechanical Prop

--Chapter 4.1.3 Visual Identification of Common Minerals

-4.1 Minerals--Homework

-4.2 Magmatic Rocks

--Chapter 4.2.1 Main Mineral Compositions of Magmatic Rocks

--Chapter 4.2.2 Texture and Structure of Magmatic Rocks

--Chapter 4.2.3 Common Classification and Identification Methods for Magmatic Rocks

--Chapter 4.2.4 Basic Characteristics of Common Magmatic Rocks Ⅰ

--Chapter 4.2.5 Basic Characteristics of Common Magmatic Rocks Ⅱ

-4.2 Magmatic Rocks--Homework

-4.3 Sedimentary Rocks

--Chapter 4.3.1 Material Compositions of Sedimentary Rocks

--Chapter 4.3.2 Texture and Structure of Sedimentary Rocks

--Chapter 4.3.3 Basic Characteristics of Common Sedimentary Rocks

-4.3 Sedimentary Rocks--Homework

-4.4 Metamorphic Rocks

--Chapter 4.4.1 Mineral Composition and their Texture andStructure

--Chapter 4.4.2 Basic Characteristics of Metamorphic Rocks

-4.4 Metamorphic Rocks--Homework

-第4章 Quiz Easy--Homework

-第4章 Quiz Enhanced--Homework

5 The Geologic Times

-5 The Geologic Times

--Chapter 5 The Geologic Times

-5 Quiz--Homework

6 The Geological Structure

-6.1 Horizontal Structure and Dipping Structure

--Chapter 6.1 Horizontal Structure and Dipping Structure

-6.2 Fold Structure

--Chapter 6.2 Fold Structure

-6.3 Fault Structure

--Chapter 6.3.1 Joint

--Chapter 6.3.2 Characteristics and Types of Faults

--Chapter 6.3.3 Fault Identification in the Wild

-6 Quiz Easy--Homework

-6 Quiz Enhanced--Homework

7 Geological Maps

-7.1 ntroduction

--Chapter 7.1.1 Types of Geological Maps

--Chapter 7.1.2 Scale of Geological Maps

-7.2 Presentation of the Geological Maps

--Chapter 7.2.1 Formation Lithology

--Chapter 7.2.2 Geological Structure

--Chapter 7.2.3 Contact Relations Between Stratas

-7.3 Reading and Analysis of the Geological Maps

--Chapter 7.3 Reading and Analysis of the Geological Maps

-7 Quiz Easy--Homework

-7 Quiz Enhanced--Homework

8 Ground Water

-8.1 Basic Conceptuals

--Chapter 8.1 Basic Conceptuals

-8.1 Basic Conceptuals--Homework

-8.2 Reservation and Movements of Ground Water

--Chapter 8.2 Reservation and Movements of Ground Water

-8.2 Reservation and Movements of Ground Water--Homework

-8.3 Movements of the Ground Water

--Chapter 8.3 Movements of the Ground Water

-8.3 Movements of the Ground Water--Homework

-8.4 Ground Water Quality

--Chapter 8.4 Ground Water Quality

-8.4 Ground Water Quality--Homework

-8.5 Ground Water Related Issues on Engineering Geology

--Chapter 8.5 Ground Water Related Issues on Engineering Geology

-8.5 Ground Water Related Issues on Engineering Geoligical Problem--Homework

-8 Quiz Easy--Homework

-8 Quiz Enhanced--Homework

9 Geological Engineering Attributes of Soils

-9.1 Soil Mass

--Chapter 9.1 Soil Mass

-9.1 Soil Mass--Homework

-9.2 Attributes of Soils

--Chapter 9.2.1 Physical Properties of Soil

--Chapter 9.2.2 Water-Physical Properties of Soil

--Chapter 9.2.3 Mechanical Properties of Soil

-9.2 Attributes of Soils--Homework

-9.3 Engineering Classification of Soils

--Chapter 9.3 Engineering Classification of Soils

-9.4 Special Soils and Its Engineering Attributes

--Chapter 9.4.1 Soft Soil and Its Engimeering Attributes

--Chapter 9.4.2 Loess and Its Engineering Attributes

--Chapter 9.4.3 Expansive Soil adn Its Engineering Attributes

-9.4 Special Soils and Its Engineering Attributes--Homework

-9 Quiz Easy--Homework

-9 Quiz Enhanced--Homework

10 Geological Engineering Attributes of Rocks

-10.1 Introduction

--Chapter 10.1 Introduction

--10.1 Introduction--Homework

-10.2 Physical and Water-Physical Properties of Rocks

--Chapter 10.2 Physical and Water-Physical Properties of Rocks

--10.2 Physical and Water-Physical Properties of Rocks--Homework

-10.3 Mechanical Properties of Rocks

--Chapter 10.3.1 Deformation Characteristics

--Chapter 10.3.2 Strength

--10.3 Mechanical Properties of Rocks--Homework

-10.4 Structural Plane and Structural Body of Rock Mass

--Chapter 10.4 Structural Plane and Structural Body of Rock Mass

--10.4 Structural Plane and Structural Body of Rock Mass--Homework

-10.5 Features and Mechanical Properties of the Structural Plane

--Chapter 10.5.1 Properties of Structural Plane

--Chapter 10.5.2 Mechanical Properties of Structural Plane

--10.5 Features and Mechanical Properties of the Structural Plane--Homework

-10.6 Mechanical Properties of Rock Mass

--Chapter 10.6 Mechanical Properties of Rock Mass

--10.6 Mechanical Properties of Rock Mass--Homework

-10.7 Engineering Classification of Rock Mass

--Chapter 10.7.1 Engineering Classification of Rock Mass Ⅰ

--Chapter 10.7.2 Engineering Classification of Rock Mass Ⅱ

--10.7 Engineering Classification of Rock Mass--Homework

-10 Quiz Easy--Homework

-10 Quiz Enhanced--Homework

11 Analysis on the Stability of Slopes

-11.1 Slope Deformation and Destruction

--Chapter 11.1.1 Slope Deformation

--Chapter 11.1.2 Slope Destruction

-11.1 Analysis on the Stability of Slopes--Homework

-11.2 Factors on the Stability of Slopes

--Chapter 11.2 Factors on the Stability of Slopes

-11.3 Analysis on the Stability of Slopes

--Chapter 11.3 Analysis on the Stability of Slopes

-11.3 Analysis on the Stability of Slopes--Homework

-11.4 Structural Analysis Method on Rocky Slope Stability

--Chapter 11.4.1 Stereographic Projection Method Ⅰ

--Chapter 11.4.2 Stereographic Projection Method Ⅱ

-11.5 Measures for Preventing and Controlling the Slope Deformation

--Chapter 11.5 Measures for Preventing and Controlling the Slope Deformation

-11.5 Measures for Preventing and Controlling the Slope Deformation--Homework

-11 Quiz Easy--Homework

-11 Quiz Enhanced--Homework

12 Geological Engineering Analysis on Stability of the Adjacent Rocks of Underg

-12.1 Underground Caverns and the Stress Distribution

--Chapter 12.1 Underground Caverns and the Stress Distribution

-12.1 Underground Caverns and the Stress Distribution--Homework

-12.2 Deformation and Destruction of the Adjacent Rocks

--Chapter 12.2.1 Brittle Adjacent Rock

--Chapter 12.2.2 Plastic Surrounding Rock and Surrounding Rock Stability Sign

-12.3 Factors on Stability of the Adjacent Rocks

--Chapter 12.3 Factors on Stability of the Adjacent Rocks

-12.4 Measures for Preventing Instability of the Adjacent Rocks

--Chapter 12.4 Measures for Preventing Instability of the Adjacent Rocks

-12 Quiz--Homework

13 Analysis on the Stability of the Rock Mass of the Ground Work

-13.1 Dam Foundation of the Water Conservancy Project

--Chapter 13.1.1 Dam Types and Requirements for Engineering Geological Conditions

--Chapter 13.1.2 Deformation Failure Mode and Stability Analysis

-13.2 Common Methods of Foundation Constructions

--Chapter 13.2 Common Methods of Foundation Constructions

-13 Quiz--Homework

14 Geological Engineering Analysis on the Reservoir Construction

-14.1 Reservoir Leakage

--Chapter 14.1 Reservoir Leakage

-14.2 Stability of the Reservoir Bank

--Chapter 14.2 Stability of the Reservoir Bank

-14.3 Reservoir Surrounding Immersions and Sedimentations

--Chapter 14.3 Reservoir Surrounding Immersions and Sedimentations

-14 Quiz--Homework

15 Methods and Technics of Engineering Geological Exploration

-15.1 Introduction

--Chapter 15.1 Introduction

-15.2 Engineering Geological Mapping

--Chapter 15.2.1 Research Content

--Chapter 15.2.2 Structural Plane Statistics

-15.3 Engineering Geological Exploration and Field Experiments

--Chapter 15.3 Engineering Geological Exploration and Field Experiments

-15.4 Instructions on the Geological Compass

--Chapter 15.4 Instructions on the Geological Compass

- Quiz--Homework

chapter 3.2.1 Physical Weathering笔记与讨论

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