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Transcript
本学期不再统一设置成绩构成,按照学校文件, 成绩构成各学院按原来通知的方式自行设置。考 试课成绩评定主要包含卷面、课堂测验(不少于 计划学时的1/5次)、课程小论文(教师自定讲 授课程是否引入小论文)、平时与作业,其中卷 面不低于50%,课堂测验不低于20%。不采用上 述成绩评定方式的,书面陈述理由,教研室主任 签署意见、教学院长审核、教务处审批。课堂测 验、课程论文、平时与作业三要素的成绩应在学 生考试前公布。考查课由任课老师自定。 60%, 20%,10%,10% INTRODUCTION TO SOIL MECHANICS ! WHAT IS IT? Soil mechanics is the science of equilibrium and motion of soil bodies. Here soil is understood to be the weathered material in the upper layers of the earth’s crust. ! WHEN WAS IT BORN? Soil mechanics has been developed in the beginning of the 20th century. The need for the analysis of the behaviour of soils arose in many countries, often as a result of spectacular accidents, such as landslides and failures of foundations. It’s official start coincides with the publication of Erdbaumechanik by Karl Terzaghi in 1925. FOUNDATIONS ! WHAT PROBLEMS DOES IT ADDRESS? FOUNDATIONS SHALLOW vs. DEEP Building Building Rock FOUNDATIONS ! WHAT ARE THE ISSUES? STRENGTH STIFFNESS FOUNDATIONS STRENGTH STIFFNESS FOUNDATIONS Including ones on the sea bottom FOUNDATIONS Metro Link Light Rail Stations, St. Louis, MO California Palace of the Legion of Honor, San Francisco, CA SLOPES/LANDSLIDES ! WHAT ARE THE ISSUES? 1 ?? ?? STABILITY SLOPES/LANDSLIDES Jizukiyama Landslide, Japan, 1985 Vagnhärad Landslide, Sweden, 1997 RETAINING STRUCTURES ! WHAT ARE THE ISSUES? STABILITY RETAINING STRUCTURES Cantilever Wall Anchored Wall RETAINING STRUCTURES Boston Central Artery Project – The Big Dig DAMS ! WHAT ARE THE ISSUES? STABILITY SEEPAGE DAMS Before …and after failure …during Teton Dam, Idaho. Failed June 5, 1976 EARTHQUAKES Niigata, Japan 1964 Adapazari, Turkey 1999 Introductio n What’s the soil ? rock earth weathering grain stores earth soil: is a complex mixture of inorganic matters and other substances, formed by the process of weathering. Why is Soil Mechanics Important? • Virtually everything that civil engineers build must be built on or with soil. • The performance of constructed facilities most often depend on soil Introductio What’s included by soil mechanics ? n base and main line forerunner permeation characteristic deformation characteristic strength characteristic specific application Chapter 1 Physical properties and Chapter 2 Soil of permeability classification soil and seepage problems Chapter 3 Calculation of stress in soil Chapter 4 Compressibility of soil and calculation ground of Chapter 5 Shearofstrength settlement soil chapter6-8 Introduction How to learn soil mechanics well? notice basic characteristic of soil - through contrast with other materials pay attention to link theory with practice through field observation and test study method concept,principle,method relation among contents need memory ,but needn’t rote Jobs • Work with geotechnical specialty firm or with larger consulting firm • Frequently out in field • Interact with other disciplines MULTIDISCIPLINARY OTHER DISCIPLINES THAT WE INTERACT WITH: • • • • • • Hydrology Geology Structural Engineering Environmental Engineering Pavement Engineering Materials Engineering THE CHALLENGE WHAT ARE THE CHALLENGES? • Soil is a complicated material that exhibits complex behavior • Soils are encountered in a seemingly infinite number of forms • Spatial variability may be substantial even at a given site • Boring and sampling gives a very incomplete description • Behavior often governed by “defects” • soil mechanics and geotechnical engineering always involves uncertainty • Strong use of analytical tools and empirical basis