直到18世纪后半叶以科学为依据的土力学有关的问题才得到一些进展,这时法国物理学家 Charles- Augustin de coulomb发表了他的土压力理论(1773)。在1857年苏格兰工程师 Willi
am rankine提出了土体平衡理论并用于基础工程的一些基本问题。尽管这两个理论有着错误,即所有土缺少黏结力类似干砂,但它们依然构成了估算土压力常用方法。20世纪的进步是在计算中考虑了黏结力;知道了土总的基本物理特性和在特定条件下的塑性;系统研究了土的剪切特性,即在滑动条件下的表现。
Both coulomb's and rankine's theories assumed that the surface of rupture of soil subjected to a shearing force is a plane . while this is a reasonable approximation for sand, cohesive soils tend to slip along a curved surface . in the early 20th century , swedish engineers propod a circular arc as the surface of slip . during the last half century considerable progress has been made in the scientific study of soils and in the application of theory and experimental data to engineering design .
Coulomb和 Rankine理论假定土受到剪切破坏面是一个平面。这对砂土基本可行,黏土滑动沿着曲面。在20世纪早期,瑞典工程师提出滑动面是一个圆弧。在最近半个世纪为了工程设计在土的科学研究、理论应用和实验资料方面取得不少进步。
a significant advance was made by the german engineer karl terzaghi , who in 1925 publi
shed a mathematical investigation of the rate of consolidation of clays under applied pressures . his analysis , which was confirmed experimentally , explained the time lag of ttlements on fully waterlogged clay deposits . terzaghi coined the term soil mechanics in 1925 when he published the book "earth--building mechanics".
一个重要成就就是由德国工程师 Karl terzaghi得到的,他在1925年发表了在加压条件下,黏土固结速率的数学分析。他的分析由实验证实并解释了饱水黏土沉陷时间滞后效应。他于1925年出版了《土一建筑力学》一书并提出土力学这一术语。decently
Rearch on subgrade materials , the natural foundation under pavements , was begun about 1920 by the u.s. bureau of public roads . veral simple tests were correlated with the properties of natural soils in relation to pavement design . in england . the road rearch Board was t up in 1933 . in 1936 the first international conference on soils was held at Harvard university .
在路基材料研究方面,道路下的天然地基大约是在1920年由美国垦务局开始研究的。有几种试件实验涉及到路基设计天然土的性质。在英国,道路研究委员会于1933年成立。1936年
关于土的第一次国际会议在哈佛大学举行。
Today ,the civil engineer relies heavily on the numerical results of tests to reinforce experience and correlate new problems with established solutions . obtaining truly reprentative samples of soils for such tests , however , is extremely difficult ; hence there is a trend toward testing on the site instead of in the laboratory , and many important properties are now evaluated in this way.
今天,土木工程师多依赖于试验成果增加经验并把新问题与建立的解联系起来。对试验来说获得有代表性的土样是非常困难的;由此趋于现场试验替代室内试验,许多重要特性以这一方式评价。
2 engineering properties of soils
speakerbox二、土的工程性质
留学品牌数字大写怎么写The properties of soils that determine their suitability for engineering u include internal friction , cohesion , compressibility , elasticity , permeability , and capillarity .
