1、shear force

shear force發(fā)音

英：　　美：

shear force中文意思翻譯

常見釋義：

[力]剪力，剪切力

shear force雙語使用場景

1、Abstract: shear force is interrelating with width and thickness of plate and obliquity of knife-edge.───文摘：斜刃剪切時，剪切力的大小與板料的寬度、厚度及斜刃傾角有關(guān)。

2、Shear force is interrelating with width and thickness of plate and obliquity of knife - edge.───斜刃剪切時,剪切力的大小與板料的寬度、厚度及斜刃傾角有關(guān).

3、Shear force is implicit in the development of bending moments.───桿中的剪力在彎矩的推導(dǎo)中是不明顯的.

4、Shear force is interrelating with width and thickness of plate and obliquity of knife-edge.───剪切時，剪切力的大小與板料的寬度、厚度及斜刃傾角有關(guān)。

5、For any load the function from load is in multiplication shear force by antisymmetry load.───任意荷載的作用含反對稱荷載分量的圖乘剪力的作用.

6、Shear force diagrams are drawn in the manner indicated, with negative shears below the baseline.───剪力圖按指明的方式來畫, 負(fù)剪力畫在基線以下.

7、Abstract: Shear force is interrelating with width and thickness of plate and obliquity of knife - edge.───文摘: 斜刃剪切時,剪切力的大小與板料的寬度、厚度及斜刃傾角有關(guān).

8、The new self suction phase - dispersing reactor can produce good dispersing effect at low shear force.───自吸式相分散器對溶液的剪切力較低,分散效果好.

shear force相似詞語短語

1、shear zone───剪切區(qū)域；[地質(zhì)]剪碎帶

2、nuclear force───[物]核力

3、the force───軍力；警察；原力（歌名，TheForce）；鐵警雄風(fēng)（**名，TheForce）

4、swear for───保證；擔(dān)保

5、spent forces───消耗的兵力

6、sheer force of───純粹的力量

7、weak force───弱作用力；弱核力；弱相互作用

8、spent force───消耗的兵力

9、special force───特殊力量

2、Shear Strength Tests

The shear strength of a soil is a basic geotechnical engineering parameter and is required for the analysis of foundations，earthwork，and slope stability problems. The shear strength of the soil can be determined in the field ( e. g. ，by a vane shear test) or in the laboratory.

There are many types of shear strength tests that can be performed in the laboratory. The objective is to obtain the shear strength of the soil. Laboratory tests are generally divided into two categories:

Shear strength tests based on total stress. The purpose of these laboratory tests is to obtain the undrained shear strength suof the soil or the failure envelope in terms of total stress ( total cohesion c and total friction angle φ) . These types of shear strength tests are often referred to as undrained shear strength tests.

Shear strength tests based on effective stress. The purpose of these laboratory tests is to obtain the effective shear strength of the soil based on the failure envelope in terms of effective stress ( effective cohesion c' and effective friction angle φ') . These types of shear strength tests are often referred to as drained shear strength tests.

The types of common laboratory tests used to obtain the shear strength of the soil are as follows:

Vane Tests. The vane shear test ( VST ) can be performed in the field to obtain the undrained shear strength suof clay. The miniature vane or torvane device could also be used in the laboratory to obtain the undrained shear strength suof clay.

Unconfined compression test. The unconfined compression test is a very simple type of test that consists of applying a vertical compressive pressure to a cylinder of laterally unconfined clay. The vertical compressive pressure that causes shear failure of the clay is termed the unconfined compressive strength qu. Some clays are so plastic that instead of shearing，they deform and bulge，and in these cases the unconfined compressive strength quis defined as the vertical compressive pressure at 15% axial strain.

The unconfined compressive test should not be performed on dry and crumbly soils， fissured or varved clays，silts，peat，and all types of granular material. The ratio of height to diameter of the cylinder of clay should be between 2 and 2. 5. The clay specimen should also be tested in standard laboratory equipment that can accurately record the force applied to the top of the clay specimen as well as record the vertical deformation of the specimen as it is loaded. Typical loading rates of the clay specimen are 0. 5 to 2 percent of the initial height L0per minute.

Unconsolidated undrained triaxial compression test. The unconsolidated undrained triaxial compression test is similar to the unconfined compression test，except that clay specimens are subjected to a confining fluid pressure in a triaxial chamber. The cylindrical clay specimen is placed in the center of the chamber，sealed with a rubber membrane，and subjected to a confining fluid pressure. A vertical pressure is slowly applied to the top of the specimen by slowly loading the piston. No drainage of the clay specimen is allowed during the test. The clay specimen is sheared in compression without drainage at a constant rate of axial deformation ( strain controlled) .

If the clay specimens are saturated，the confining pressure will not change the wet density of the specimen. Therefore，if several identical clay specimens are tested，they will all have approximately the same undrained shear strength ( failure envelope will be a horizontal line) . Since this test does not provide any additional information for saturated clay specimens，it is used much less frequently than the unconfined compression test.

Consolidated undrained triaxial compression test. The consolidated undrained triaxial compression test is similar to the unconsolidated undrained compression test，except that the clay specimen is first consolidated prior to shearing. This test can also be used to measure the excess pore water pressures that develop within the clay as it is sheared. The shear strength based on total stress or based on effective stress ( by measuring the pore water pressure during shear) can be obtained from this laboratory test. The test is quite complicated and should be performed only by experienced personnel. This test has been used to study the shear behavior of all types of soil.

Direct shear test. The direct shear test，first used by Coulomb in 1776，is the oldest type of shear testing equipment. The direct shear test is also the most common testing method to obtain the drained shear strength of a soil. Figure 5. 2 shows the direct shear testing device. The testing procedure is as follows:

1) The soil specimen ( typical diameter = 63. 5 mm and height = 25. 4 mm ) is placed on top of a porous plate in the center of the direct shear apparatus.

2) A porous plate is placed on the top of the specimen and a dial gauge is set up to measure vertical deformation.

3) A loading device is used to apply a vertical force to the soil specimen. This vertical force，also known as the normal force，is converted to a stress by dividing the vertical force by the cross-sectional area of the soil specimen.

4) A surrounding container allows the soil specimen to be submerged in distilled water.

5) The soil specimen is allowed to equilibrate or fully consolidate under the applied vertical stress.

6) A dial gauge is set up to measure horizontal deformation and then an increasing force is applied to the upper half of the direct shear apparatus. The shear force can be applied by using deadweights placed on a hanger ( stress-controlled test) or by a motor acting through gears( strain-controlled test) .

7) The soil specimen is slowly sheared in half ( a single shear plane) .

8) The maximum shear force required to shear the sample is recorded and the shear strength is defined as this shear force divided by the cross-sectional area of the soil specimen.

9) The shear strength versus the vertical stress can be plotted and a failure envelope is obtained.

Figure 5. 2 Direct shear apparatus

It is important to shear the soil specimen slowly enough that excess pore water pressures do not develop within the soil specimen. For clean sands，the total elapsed time to failure should be about 10 minutes，while for silty sands the total elapsed time to failure should be about 60 minutes. For clean sands and silty sands，the setup and actual testing operation is relatively quick and simple，which is the main reason for the test's popularity.

Drained residual shear strength. The previous shear strength tests have described methods to obtain the undrained shear strength suor the shear strength parameters ( c or c' and φ or φ') that define the failure envelope. These tests normally determine the shear strength of the soil， which is defined as the shear stress at failure ( i. e. ，the peak shear strength) .

For some projects，it may be important to obtain the residual shear strength of fine- grained soil， which is defined as the remaining ( or residual ) shear strength after a considerable amount of shear deformation has occurred. For example，a clay specimen could be placed in the direct shear box and then sheared back and forth several times to develop a well-defined shear failure surface. Once the shear surface is developed，the drained residual shear strength would be obtained by performing a final，slowshear of the specimen. The drained residual shear strength can be applicable to many types of soil or rock conditions where a considerable amount of shear deformation has already occurred. For example，the stability analysis of ancient landslides，slopes in overconsolidated fissured clays，and slopes in fissured shales will often be based on the drained residual shear strength of the failure surface.

Skempton stated that the residual shear strength ( friction angle ) is independent of the original shear strength，water content，and liquidity index，and depends only on the size， shape，and mineralogical composition of the constituent particles. Besides the direct shear equipment，the drained residual shear strength can be determined by using a modified Bromhead ring shear apparatus. Back calculations of landslide shear strength indicate that the residual shear strength from the ring shear test is reasonably representative of the slip surface. The ring shear specimen is annular with an inside diameter of 7cm ( 2. 8in) and an outside diameter of 10cm ( 4in) . Drainage is provided by annular bronze porous plates secured to the bottom of the specimen container and the loading platen.

Remolded specimens are often used for the ring shear testing. A typical testing procedure is as follows:

1) The remolded specimen is typically obtained by air drying the soil，crushing it with a mortar and pestle，ball milling the crushed material，and processing it through the United States Standard Sieve No. 200.

2) Distilled water is added to the processed soil until water content approximately equal to the liquid limit is obtained. The specimen is then allowed to rehydrate for 7 days in a moist room. A spatula is used to place the remolded soil paste into the annular specimen container.

3) To measure the drained residual shear strength，the ring shear specimen is often consolidated at a high vertical pressure ( such as 700 kPa) and then the specimen is unloaded to a much lower vertical pressure ( such as 50 kPa) .

4) The specimen is then presheared by slowly rotating the ring shear base for one complete revolution using the hand wheel.

5) After preshearing，the specimen is sheared at a slowdrained displacement rate ( such as 0. 02 mm / min) . This slowshear displacement rate has been successfully used to test soils that are very plastic.

6) After a drained residual strength condition is obtained at the lowvertical pressure， shearing is stopped and the normal stress is increased to a higher pressure ( such as 100 kPa) . After consolidation at this higher pressure，the specimen is sheared again until a drained residual condition is obtained.

7) This procedure is also repeated for other effective normal stresses. The slowshear displacement rate ( 0. 02 mm / min) should be used for all stages of the multistage test.

Figure 5. 3 presents the drained residual failure envelope. It can be seen in the figure that the failure envelope is nonlinear，which is a common occurrence for residual soil.

Figure 5. 3 Drained residual shear strength envelope from ring shear test on slide plane material