土壤体积关系

Thephysical properties of a soilgive insight as to the identification of the soil and the determination of its characteristics and load response. These properties can be determined by performing a laboratory analysis on undisturbed soil samples obtained during the test boring process.

Thelaboratory analysisshould be performed in accordance with the following ASTM Standard:

D-854: Test Method for Specific Gravity of Soils

It should be noted that laboratory analyses are performed under controlled conditions with exacting materials and equipment. The results of such analyses may be considered to be accurate.

A field不受干扰的土壤样本将含有三种单独和不同的成分 - 固体，水和空气。

必须在实验室分析中确定的重要属性之一是weight-volume relationship这些成分。可以在视觉上示出该土壤样品的化妆，如图1所示，其中Vrepresents volume,Wrepresents weight, and the subscriptsa,w,和srepresent air, water, and solids.

The general procedure by which the weight and volume are determined is itemized below:

Step 1.

Select the sample to be tested and determine its total volumeV.The units of volume are usually cubic centimeter (cm³).

Step 2.

称重样品以确定其重量W,in g. Note that this weight includes both the weight of the water and the solid constituents.

Step 3.

The weight of the solid constituentsw.must now be determined. The sample is first oven dried at a constant temperature of 105 to 115 degrees Centigrade. This will drive off all of the free water from the sample. If there are any clay particles in the sample the drying process will also remove the absorbed water molecularly bonded to those particles.

The sample which remains after the drying process consists solely of solid constituents, whose weight can now be determined.

Step 4.

水的重量W_woriginally contained in the sample can be determined by subtracting the weight of the solids from the initial weight of the sample:

W_w= W-W_s

Step 5.

The volume of water V_w, corresponding to the weight of water found in Step 3, may now be computed. Remember that density is the ratio of weight to volume, and that the density of water is 1 g/cm³; therefore:

V_w= W_w

Step 6.

通过将固体从步骤3放入已知体积的容器中，可以通过将固体放入容器中的固体V的体积，并用仔细测量体积的水填充容器。这两种体积之间的差异表示固体的体积。

The weights and volumes obtained by these measurements can be used to determine important physical properties of the in-situ soil from which the undisturbed sample was obtained.