《土质学与土力学》第1章绪论.ppt

土质学与土力学,南京工业大学,土木工程学院,绪 论,土力学研究内容 土力学课程内容 土力学发展史 生活中的土力学 古代工程中土力学的运用 比萨斜塔,土力学研究内容,研究土的物理、化学和力学性质及土体在荷载、水、温度等外界因素作用下工程性状的应用科学。,土力学的三大问题,.土的变形特性,.土的强度特性,3 .土的渗透特性,土的物理性质和工程分类 土的渗透性和渗流 土体中的应力计算 土的压缩性和地基沉降计算 土的抗剪强度 土压力 土坡稳定分析 地基承载力,土力学课程内容,土力学发展史,本学科理论基础的发端，始于18世纪兴起厂工业革命的欧洲。那时。随着资本主义工业化的发展，工场手工业转变为近代大工业，建筑的规模扩大了。为了满足向国内外扩张市场的需要，陆上交通进入了所谓“铁路时代”。因此，最初有关土力学的个别理论多与解决铁路路基问题有关。,土力学发展史,l773年，法国的C.A.库伦(Coulomb)根据试验创立了著名的砂土抗剪强度公式提出了计算挡土墙土压力的滑楔理论。,90余年后，英国的W. 朗肯(Rankine, 1869)又从另 一途径提出了挡土墙土压力理论。这对后来土体强度理论的发展起了很大的作用。,法国J.布辛奈斯克(Boussinesq,1885)求得了弹性半空间在竖向集中力作用下的应力和变形的理论解答。,瑞典W费尔纽斯(Fellenius,1922) 为解决铁路塌方问题作出了土坡稳定分析法。这些古典的理论和方法，直到今天。仍不失其理论和实用的价值。,土力学发展史,在长达一个多世纪的发展过程中，许多研究者承继前人的研究，总结了实践经验。为孕育本学科的雏形而作出贡献。1925年，K.太沙基( Terzaghi)归纳发展了以往的成就发表了土力学(Erdbaumechanik )一书。接着，这些比较系统完整的科学著作的出现，带动了各国学者对本学科各个方面的探索。从此，上力学及地基基础就作为独立的科学而取得个断的进展。,The Grandfather of Soil Mechanics,Charles Augustin de Coulomb (1736 - 1806),William John Maquorn Rankine (1820 - 1872),The Father of Soil Mechanics,Terzaghi, a geologist. He won the Norman Medal of ASCE four times. He was given nine honorary doctorate degrees from universities in eight different countries.He started modern soil mechanics with his theories of consolidation, lateral earth pressures, bearing capacity, and stability.,Karl von Terzaghi (1923-1963 ),A.W. Skempton was a well-respected and accomplished professor at Imperial College in the University of London,A. W. Skempton,Darcys Law is a generalized relationship for flow in porous media. It shows the volumetric flow rate is a function of the flow area, elevation, fluid pressure and a proportionality constant.,Henry Philibert Gaspard Darcy (1803-1858),Being a pioneer, professor Casagrande worked on the fundamental problems of Soil Mechanics, such as soil classification, seepage through earth, and shear strength. It is safe to assume that the “A-Line“ on the plasticity chart is after “Arthur”.,Arthur Casagrande (1902-1981),Daniel Bernoulli,行走的土力学原理,沙滩骑车的土力学原理,David Macaulay, in his book underground (Houghton Mifflen, Boston, 1976), has illustrated the foundations and piping from the bottom up without soil. All facilities are built on, in or with earth materials. Thus, the science and engineering of soil and rock, and of the water and other fluids that permeate them are critical for addressing national issues such as infrastructure construction and re-construction, waste management, resource discovery and recovery, mitigation of natural hazards and frontier exploration and development. Geotechnics majors find careers in the broad range of disciplines that draw heavily on the elements of rock and soil mechanics and environmental geology.,？,Did you even wonder what a city would look like without soil,The use of a smooth surface for sliding on silt for raising an obelisk,古代巨大石碑 搬运中土力学原理,The bridge at Anchi ,Built around 600 A.D.,隋朝石工李春所修赵州石拱桥、不仅因其建筑和结构设计的成就而著称于世，就论其地基基础的处理也是颇为合理的。他把桥台砌置于密实租砂层上，1300多年来估计沉降约几厘米。现在验算其基底压力约500600kPa，这与以现代土力学理论方法给出的承教力值很接近。,赵州石拱桥,北宋李诚所著营造法式记载的古代地基基础的某些具体做法。,比萨斜塔,比萨斜塔自1173年9月8日动工，至1178年建至第4层中部高度约29m时，因塔明显倾斜而停工。94年后，于 1272年复工，经6年时间，建完第7层高48m，再次停工中断82年。于1360年再复工，至1370年竣工。全塔共8层，高度为55m。 塔身呈圆筒形，16层由优质大理省砌成，顶部78层采用砖和轻石料。塔身每层都有精美的圆柱与花纹图案，是一座宏伟而精致的艺术品。,The tower from the west side before the reopening ceremony on June 16 2001,Cross section of the tower,土体滑坡,加拿大特郎斯康谷仓的地基破坏事故,加拿大特郎斯康谷仓由65个圆柱形筒仓组成，高31m，底面长59.4m。其下为钢筋混凝土片筏基础，厚2m。谷仓自重20万kN，当装谷2