土的性質(zhì)外文翻譯

1、<p>　　1.2.2 Water in a Soil Mass</p><p>　　As regards water in the soil,we differ among gravitational water or ground water,capillary water,bound water and interlayer water of a mineral.</p><

2、p>　　1.Gravitational water</p><p>　　The gravitational water is mainly concentrated at contact point between grains that is in steady motion under the influence of gravitational forces.There is a regular wa

3、ter table for the water. Below the water table there exists a water-saturated zone and hydrostatic water within it,The gravitational water has a negative influence on foundation soil.This form of water exists in both coa

4、rse-grained soils and finer soils,following Darcy's law.It will be discussed in details in chapter 4.</p><p>　　2.Capillary water</p><p>　　The capillary water,above the gravitational water ta

5、ble,is held by capillary force (surface tension force) that is governed by the surface tension of grains and the diameter of voids.The height, Hc, to which water will rise in a capillary tube (void space) , is, theoretic

6、ally,directly proportional to the surface tension force T, divided by the diameter of the tube d:</p><p>　　So the height of the capillary zone (the occupied area of capillary water) will also be affected by

7、the cleanness of the water; it could be much less for pollutes water. According to Terzaghi and Pech (1967) ,the Hc can be giver as:</p><p>　　Where Hc ——maximum height of capillary size, in mm, relates to mi

8、nimum pore size;</p><p>　　e ——void ratio;</p><p>　　d10 ——effective size, mm;</p><p>　　c ——constant,10~20 mm2 (for clean water) .</p><p>　　Capillary rising depends on gr

9、ain size distribution. As always, the smaller the grain is, the higher the capillary rises, except for some of clay particles that is filled with bound water surrounding the grains. As a geotechnique engineer, you should

10、 be aware of a big difference between the capillary water and the gravitational water: the water-saturated zone filled with the gravitational water has hydrostatic pressure, while pore water pressure produced by the capi

11、llary water should be negative</p><p>　　3.Bound water</p><p>　　In the fine-grained soils,the grain surface has an ionized layer around them, which is defined as bound water. More and more people

12、 have known that the cohesion force,which is against shearing stress, is to a large extent, resulted from the bound water. The plastic properties of clay soil such as swelling and shrinkage of clay, is mainly attached to

13、 the bound water. It is a very important factor considered in the design of a foundation. See Fig. 1-4.</p><p>　　4.Interlayer water</p><p>　　The interlayer water is hidden in a mineral. For exam

14、ple, the mineral,montmorillonitic has a layer structure, its interlayer space,is typically filled with water,originally filled, or filled later. Depending on the abundance or deficiency of water occupy this space, a mont

15、morillonitic soil may exhibit its marked properties of swelling and shrinkage.The montmorillonitic soil, as a loaded foundation, is very unstable when water is present.</p><p>　　1.2.3 Gas in a Soil Mass</

16、p><p>　　As always, gas basically exists in a soil mass. We differ between opened gas and closed gas. The opened gas is interconnected, and directly flows to atmosphere, while the closed gas retains.The former a

17、lways takes place in the coarse-grained soil,which has little influence on the engineering properties of the soil. But the latter is so difficult to escape that there is a high compressibility and a low permeability for

18、the soils.Geotechnical engineers should know that the presence of gas in the s</p><p>　　1.2.4 The Structural Features of a Soil Mass</p><p>　　1.Different Layers of Soil</p><p>　　For

19、 the sedimentary formations, no matter whether they are wind-deposited,water-deposited or glacial-deposited, it is natural that there are different layers of soil,fine-grained soil or coarse-grained soil.Fine-grained lay

20、ers are often embedded in coarse-grained layers and vice versa. We can also say,from the soil mechanics point of view, high bearing capacity (or Low compressive) layers are often embedding in low bearing capacity and vic

21、e versa. These different layers of soil will cause the pr</p><p>　?。?）Long-term settlement if there are weak layers (existed).</p><p>　　（2）Differential settlement of buildings (superstructure) d

22、ue to the layers' thickness change in horizontal direction.</p><p>　?。?）Landslide along a thin and weak layer (such as clay or silt) when deep excavating for foundation.</p><p>　　It is empha

23、sized that the weak layers of soil will be carefully studied in the building site for a successful foundation design.</p><p>　　2.Non-homogeneities (Homogeneousness)</p><p>　　Absolutely, soils ar

24、e non-homogeneities materials that are different in deformation and strength in all directions. The non-homogeneities characteristics of soil are caused by not only the variation of deposit conditions, but also the effec

25、t of stress history. With a very large variations in size and shape, most of which are sharp-edged belonging to the former, while deep-going fissures and cracks are the latter. In engineering investigation of a soil mass

26、, we should pay attention to the local n</p><p>　　1.3 Soil Configuration</p><p>　　1.3.1 Single-grained Structure</p><p>　　The primary structure for a coarse-grained soil is typicall

27、y single-grained one. The loose configuration shown in Fig. 1-5 (a) typically takes place in an active water environment such as beach sand or river gravel. But the dense soils as shown in Fig. 1-5 (b) are typically orig

28、inated in a quiet water environment. The soil with single-grained structure may serve as a natural foundation soil.</p><p>　　1.3.2 Honeycomb Structure</p><p>　　For the very fine sand or silt soi

29、l, the grain arrangement looks like the honeycombs of a bee, in term of honeycomb configuration similar to that shown in Fig. 1-6. The soil with the honeycomb configuration has the properties of loose, low strength and h

30、igh compressibility.</p><p>　　1.3.3 Fabric Structure</p><p>　　Clay soil has its special structure, fabric configuration shown in Fig. 1-7. This concept of soil structure is arrived at through th

31、e current microscopy technique. Some clay grains may exists in randomly arranged picket or pads, which individually are made up of highly oriented particles. For this configuration, you should be aware of high compressib

32、ility due to high voids in the design of a foundation.</p><p>　　Macro structure of a soil mass, such as beds,disappeared layers, lenses and deep-going fissures, are very dangerous because they are the cause

33、of high compressibility, low strength and differential settlement.</p><p>　　1.4 The Important Parameters for Two-phase and Three-phase Soils</p><p>　　From the construction point of view,soils ar

34、e also divided into in situ soils that are in place and undisturbed, and artificial soil by human beings such as embankment.Both in situ and disturbed soil usually have solid, water, and air, known as three-phase soils,

35、which can be expressed in a schematic as shown in Fig. 1-8. All parameters are expressed in terms for a soil mass (three-phase soil).</p><p>　　1.4.1 Measurement of Voids</p><p>　　Voids in soil a

36、re either expressed in terms of porosity or in terms of void ratio. Porosity n is defined as the ratio of volume of voids,Vv, to total volume of soil V and expressed as a percentage, while void ratio e is defined as the

37、ratio of volume of voids to volume of particle Vs, expressed as a decimal. They are differently expressed without any reason other than custom .</p><p>　　1.2.2 土中的水</p><p>　　關于土中的水，我們可分為重力水或地下水，

38、毛細水，結合水和礦物隔層水。</p><p><b>　　重力水</b></p><p>　　重力水主要集中在介于顆粒間的接觸點，在地心引力的影響下固定移動。這有一個規(guī)律的地下水位。在地下水位的下面存在一個水飽和層和靜力水在里面，重力水對地基土有消極影響。水的形態(tài)存在粗粒土和優(yōu)質(zhì)土中都符合達西定律。這將是在第四章中詳細討論。</p><p>&

39、lt;b>　　毛細水</b></p><p>　　毛細水，在重力水位上面，是由顆粒的表面張力和孔隙率的直徑管理毛細管力(表面張力力)。高度，在毛細管（孔隙空間）中水將會上升，從理論上來講，與表面張力力T成正比，除以管的直徑d：</p><p>　　所以毛細管水層的高度（毛細水的占地面積）也將受到潔凈水的影響；這更不用說是污水了。根據(jù)太沙基和Pech（1967），由<

40、/p><p><b>　　給出。</b></p><p>　　——毛細管徑的最大高度，單位mm，與最小孔徑有關；</p><p><b>　　e ——空隙比；</b></p><p><b>　　——實際直徑；</b></p><p>　　c ——常數(shù)，10

41、~20（對于潔凈水）。</p><p>　　毛細上升取決于粒度分布特征。像往常一樣，越小的顆粒，毛細上升得越高，除了一些周圍充滿了結合水的粘土顆粒。作為一名土力學工程師，你應該知道介于毛細水和重力水的一個很大的區(qū)別：充滿重力水的飽和水區(qū)有靜水壓力，而由毛細水產(chǎn)生的孔隙水壓力應該是消極的。</p><p><b>　　結合水</b></p><p&g

42、t;　　在細粒土中，顆粒表面有一個電離層圍繞著它們，這被定義為結合水。越來越多的人們知道了內(nèi)聚力，這反對抗剪應力，在很大程度上，是由結合水造成的。粘土塑性如粘土的膨脹和收縮，是主要系于結合水。這在地基的設計中是作為一個重要因素來考慮的。見圖1-4。</p><p><b>　　層間水</b></p><p>　　層間水隱藏在礦物中。例如，礦石富含有一層結構，其夾層空間

43、是典型的裝滿水，原來滿,或填充之后。依靠水的豐富或缺乏占領這個空間，富含土壤彰顯其明顯腫脹和收縮性能。作為裝載基礎，當水存在時，肥沃土是非常不穩(wěn)定的。</p><p>　　1.2.3 土中的氣</p><p>　　像往常一樣，氣體主要存在在土體中。我們可分為非閉合氣體和閉合氣體。非閉合氣體是連通的，直接流向大氣的，而閉合氣體保留了下來。前者通常發(fā)生在粗粒土中，這在土的工程性質(zhì)中幾乎沒有影響

44、。但后者是如此難以逃脫，因為土壤有高壓縮性和低滲透性。巖土工程師應該知道在土壤空間中存在氣體對基礎的設計有著重要意義。</p><p>　　1.2.4 土體的結構特點</p><p><b>　　1. 土的不同層</b></p><p>　　對于沉積地層，無論是否風積，水積或冰積，這有不同層的土，粗粒土和細粒土，是自然的。細粒土經(jīng)常嵌入在粗粒層

45、，反之亦然。我們也可以說，從地質(zhì)力學的觀點，高承載力（或低抗壓）層經(jīng)常嵌入在地承載力，反之亦然。這些土的不同層將導致以下這些問題：</p><p>　　如果有軟弱夾層（存在）長期的沉降。</p><p>　　由于地層的厚度在水平方向發(fā)生改變，導致上層建筑的不均勻沉降。</p><p>　　當為了基礎而深度挖掘時，會沿著一個薄弱的底層（如黏土或淤泥）山崩。</p

46、><p>　　這就強調(diào)了在一個建筑工地的成功的基礎設計中要認真研究土的軟弱夾層。</p><p><b>　　不均勻性（均質(zhì)性）</b></p><p>　　絕對的，土是不均勻物質(zhì)，它在不同方向的變形和強度都是不相同的。土的不均勻性特征不僅由沉淀物情況的變化引起，而且由應力史作用引起的。隨著尺寸和形狀非常大的變化，其中屬于前者的大部分是邊緣清晰的，

47、而深刻的裂縫是后者。在土壤質(zhì)量的工程勘察中，我們應該注意局部的不均勻性，如埋在地層的鏡片高壓縮性土具有特定的危險和常常會對建筑物造成很大的不均勻沉降。</p><p><b>　　1.3 土的結構</b></p><p>　　1.3.1 單粒結構</p><p>　　粗粒土的主要結構式典型的單粒結構。如圖1-5（a）所示，疏松結構典型地發(fā)生在活

48、性水環(huán)境中，如沙灘沙或河沙石。但如圖1-5（b）所示，典型地發(fā)生在靜水環(huán)境中。單粒結構的土可以起一個自然基礎土的作用。</p><p>　　1.3.2 蜂窩狀結構</p><p>　　對于細沙或粉砂粘土，顆粒排列好像蜜蜂的蜂窩，在蜂窩外形方面與圖1-6所示的相似。蜂窩狀的土有疏松性，低強度和高壓縮性。</p><p>　　1.3.3 絮狀結構</p>

49、<p>　　粘土有其特殊結構，絮狀結構如圖1-7所示。土結構的這個概念是通過電流顯微鏡技術得出的。一些粘土顆粒可能存在隨機安排在樁或墊，這單獨地由高導向粒子組成。對于這個結構，由于在基礎設計中的高孔隙率，你應該注意高壓縮性。</p><p>　　土體的宏觀結構，如地層，消失層，鏡頭和深刻的裂縫，是非常危險的，因為它們造成了高壓縮性，低強度和不均勻沉降。</p><p>　　1.4

50、 二相土和三相土的重要參數(shù)</p><p>　　從建筑的角度來看，土壤也分為原位土即在原地和無擾動的，和人工土如堤岸。原位土和擾動土通常都有固體，水和空氣，成為三相土，可以用圖1-8中所示的示意圖表示。所有的參數(shù)表現(xiàn)為一種土體(三相土)。</p><p>　　1.4.1 孔隙率的測量</p><p>　　土中孔隙含量既表達為孔隙度，也表達為孔隙率?？紫抖萵解釋為孔隙