M145 土壤与土壤集料的分类.doc

A1，级配良好的粗砂/砾/碎石+无塑性结合料A2，细粒含量35%且不属于A1、A3的粒状材料，一般指级配不良的粒状材料A3，细砂，不含细粒成份A4，无塑性或中等塑性粉质土，细粒含量75%A5，高液限粉质土，细粒含量75%A6，塑性黏土A7，高液限的塑性黏土技术人员培训和认证程序Classification of Soil and Soil-Aggregate Mixtures For Highway Construction PurposesAASHTO M-145-91 (2000)(Modified)用于公路施工目的的土壤及土壤集料混合物的分类AASHTO M-145-91 (2000)(修改过的)This practice describes a procedure for classifying soils into seven groups based on laboratory determination of particle-size distribution, liquid limit, and plasticity index. The group classification should be useful in determining the relative quality of the soil material for use in embankments, subgrades, and backfills. For detailed design of important structures, additional data concerning strength or performance characteristics of the soil under field conditions will usually be required. 本实践描述了用于根据颗粒尺寸分布、液限及塑性指数把土壤分为七个组的步骤。该分组对于确定用于路堤、路基和回填的土壤材料相对质量是有用的。对于重要构筑物的详细设计，通常要求关于野外条件下土壤的强度或性能特征的补充资料。Modification: Determination of Group Index will not be a part of certification, but taught as a useful tool for more accurate determination of soil classification. 修改：确定分组指数不是鉴定的一部分，但作为更精确地确定土壤分类的有用的工具而讲授。Key Elements: 要素：1. Determine sieve analysis.Determine sieve analysis using AASHTO T-11 and AASHTO T-27 test procedures (Note 1). The 2.00 mm (No. 10) sieve, 425-m (No. 40) sieve, and 75-m (No. 200) sieve must be included to determine the particle size distribution as a basis for classification. 1.确定筛析使用AASHTO T-11和AASHTO T-27测试程序确定筛析。作为分类的基础，2mm（10号）筛、425m（40号筛）和75m（200号）筛必须被包括以确定颗粒尺寸分布。2. Determine the liquid limit.Determine the liquid limit of the material using AASHTO T-89 test procedures.2.确定液限使用AASHTO T-89测试程序来确定材料的液限。3. Determine the plastic limit.Determine the plastic limit and plasticity index of the material using AASHTO T-90 test procedures.3.确定塑限使用AASHTO T-90测试程序来确定材料的塑限和塑性指数。4. Determine classification of material.Using the test limits shown in Table 1 of AASHTO M-145, make the classification of the material. If a more detailed classification is desired, a further subdivision of the groups may be made using Table 2 of AASHTO M-145 (3.1). With required test data available, proceed from left to right in Table 1 or Table 2 and the correct group will be found by process of elimination (3.2).The first group from the left into which the test data will fit is the correct classification (3.2).4.确定材料类别使用AASHTO M-145表1所列测试界限来进行材料分类。如果要求更精确的材料分类，可以使用AASHTO M-145（3.1）表2来进行进一步的细分。用现有的所需测试资料在表1或表2中从左到右进行，正确的组将通过排除法被找到。从左边开始测试资料第一个符合的组就是正确的分类。5. Report classification.All limiting test values are shown as whole numbers. If fractional numbers appear on test reports, convert to the nearest whole number for purposes of classification (3.2).5.分类报告所有测试界限值都以整数表示。如果在测试报告中出现小数，为分类目的要转换为最接近的整数。DESCRIPTION OF SOIL CLASSIFICATION GROUPS: 土壤分组描述：Soil Fractions: According to the AASHTO system, soils are divided into two major groups as shown in Table 1 of AASHTO M-145. These are the granular materials with 35 percent or less passing the 75-m (No. 200) sieve (5.1) and the silt-clay materials with more than 35 percent passing the 75-m (No. 200) sieve (5.2). Moreover, five soil fractions are recognized and often used in word descriptions of a material. These five fractions are defined as follows: 土壤粒级：根据AASHTO系统，土壤划分为如AASHTO M-145表1所示的两个主要群组。它们是有着通过75-m（200号）筛（5.1）少于等于35%的粒状材料和有着通过75-m（200号）筛（5.2）部分大于35%的粉-黏土材料。此外，5个粒级被确认并常常用于描述材料的词中。这五个粒级定义如下：Boulders and Cobbles material retained on the 75 mm (3 in.) sieve. They should be excluded from the portion of a sample to which the classification is applied, but the percentage of such material should be recorded (4.1.5).漂石与卵石留在75mm筛上的材料。它们应被从分类所使用样品中排除，但这样的材料的百分比应被记录（4.1.5）。Gravel materials passing sieve with 75 mm (3 in.) square openings and retained on the 2.0 mm (No. 10) sieve (4.1.1).砾石通过75mm方形开口并保留在2mm筛（10号）上的材料（4.1.1）。Coarse Sand materials passing the 2.0 mm (No. 10) sieve and retained on the 425-m (No. 40) sieve (4.1.2).粗砂通过2mm筛并保留在425-m（40号）筛之上的材料（4.1.2）。Fine Sand materials passing the 425-m (No. 40) sieve and retained on the 75-m (No. 200) sieve (4.1.3).细砂通过425-m筛并保留在75-m（200号）筛上的材料（4.1.3）。Combined Silt and Clay material passing the 75-m (No. 200) sieve. The word “silty” is applied to a fine material having a Plasticity Index of 10 or less, and the term “clayey” is applied to fine material having a PI of more than 10 (4.1.6).合并粉土与黏土通过75-m筛的材料。“粉质”这个词用于塑性指数小于等于10的细粒材料。而“黏质”这个词用于塑性指数大于10的材料（4.1.6）。GRANULAR MATERIALS:粒状材料：Group A-1: Well-graded mixtures of stone fragments or gravel ranging from coarse to fine with a non-plastic or slightly plastic soil binder (5.1.1). However, this group also includes coarse materials without soil binder.组A-1：由一系列含无塑性或轻微塑性土结合料的从粗到细的石头碎块或砾石所组成的级配良好的混合物（5.11），然而，该组也包括不含土结合料的粗粒材料。Subgroup A-1-a:Materials consisting predominantly of stone fragments or gravel, either with or without a well graded soil binder (5.1.1.1).亚组A-1-a：材料主要由含或不含级配良好土结合料的石头碎块或砾石组成（5.1.1.1）。Subgroup A-1-b: Materials consisting predominantly of coarse sand either with or without a well-graded soil binder (5.1.1.2). 亚组A-1-b：材料主要由含或不含良好级配土结合料的粗砂组成。Group A-3: Material consisting of sands deficient in coarse material and soil binder. Typical is fine beach sand or fine desert blow sand, without silt or clay fines or with a very small amount of non-plastic silt. This group also includes stream deposited mixtures of poorly graded fine sand and limited amounts of coarse sand and gravel (5.1.2). These soils make suitable subgrades for all types of pavements when confined and damp. They are subject to erosion and have been known to pump and blow under rigid pavements. (Information:They can be compacted by vibratory, pneumatic-tired, and steel-wheeled rollers but not with a sheepsfoot roller.)组A-3：由缺乏粗粒材料和土结合料的砂所组成的材料。典型者如海滩砂或沙漠飞砂，不含粉土或黏土细粒或含非常少量的无塑性粉土。该组也包括河流沉积的不良级配细砂与数量有限的粗砂和砾石的混合物（5.1.2）。密闭和防潮的情况下其可以作为各种类型路面的基床。众所周知其在刚性路面下其易于受冲刷并喷涌。（信息：它们可以通过振动式、气胎式以及钢轮式压路机来碾压，但不用羊足碾。）Group A-2: This group includes a wide variety of “granular” materials that are borderline between the materials falling in Groups A-1 and A-3 and silt-clay materials of Groups A-4, A-5, A-6 and A-7. It includes all materials containing 35 percent or less passing the 75-m (No. 200) sieve that cannot be classified as A-1 or A-3 (5.1.3).组A-2：该组包括组A-1、组A-3及粉-黏土材料的组A-4、A-5、A-6和A-7范围之外的各种各样的“粒状材料”。它包括了所有通过75-m (200号)筛含量小于等于35%的不能被归于A-1或A-3（5.1.3）的材料。Subgroups A-2-4 and A-2-5: Include various granular materials containing 35 percent or less passing the 75-m (No. 200) sieve, and with that portion passing 425-m (No. 40) sieve having the characteristics of the A-4 and A-5 groups. These groups include such materials as gravel and coarse sand with silt contents or Plasticity Indexes in excess of the limitations of Group A-1, and fine sand with non-plastic silt content in excess of the limitations of Group A-3 (5.1.3.1).亚组A-2-4和A-2-5包括通过75-m (200号)筛含量小于等于35%、通过425-m (40号)筛的部分具有组A-4和组A-5特征的各种各样的材料。这些组包括粉土成份或塑性指数超出组A-1限值的砾石和粗砂，以及含有无塑性粉土成份超出组A-3限值的的细砂Subgroups A-2-6 and A-2-7: Include materials similar to those describe under Subgroups A-2-4 and A-2-5, except that the fine portion contains plastic clay having the characteristics of the A-6 or A-7 group (5.1.3.2).亚组A-2-6和A-2-7：包括与亚组A-2-4和A-2-5下所描述的那些相似的材料，但是细粒部分所含的塑性黏土具有组A-2-6或A-2-7的特征。A-2 soils are given a poorer rating than A-1 soils because of inferior binder, poor grading, or a combination of the two. Depending on the character and amount of binder, A-2 soils may become soft during wet weather and loose and dusty in dry weather when used as a road surface. If, however, they are protected from these extreme changes in moisture content, they may be quite stable. The A-2-4 and A-2-5 soils are satisfactory as base materials when properly compacted and drained. A-2-6 and A-2-7 soils with low percentages of minus 75-m (no. 200) sieve material are classified as good bases, whereas these same soils with high percentages of minus 75-m (No. 200) sieve and PIs of 10 or higher are questionable as a base material. Frequently, the A-2 soils are employed as a cover material for very plastic subgrades.因为劣等的结合料、差的级配或两者的组合，A-2土壤与A-1土壤相比评分较差。根据结合料的特征和数量，A-2土壤当做为路面时在雨天可能变软，而在干天变得松散多尘。然而，如果避免含水量极端的变化，其可以很稳定。A-2-4和A-2-5土壤在适当地被碾压和排水时可满足被作为基料的要求。有着低百分比的通过75-m (200号)筛含量的A-2-6和A-2-7土被归作好的基料，而塑性指数大于等于10者作为基料是有疑问的。A-2土壤常常被当作塑性很强基床的覆盖材料。SILT-CLAY MATERIALS:粉土-黏土材料Group A-4: The typical material of this group is a non-plastic or moderately plastic silty soil usually having 75 percent or more passing the 75 m (No. 200) sieve. The group includes also mixtures of fine silty soil and up to 64 percent of sand and gravel retained on the 75-m (No. 200) sieve (5.2.1). These predominantly silty soils are quite common in occurrence. Their texture varies from sandy loams to silty and clayey loams. With the proper amount of moisture present, they may perform well as a pavement component. However, they frequently have an affinity for water and will swell and lose much of their stability unless properly compacted and drained. Moreover, they are subject to frost heave. These soils do not drain readily and may absorb water by capillary action with resulting loss in strength. The silty loams are often difficult to compact properly. Careful field control of moisture content and pneumatic tired rollers are normally required for proper compaction.组A-4：该组的典型材料是无塑性或中等塑性粉质土，通常通过75-m (200号)筛含量大于等于75%。该组也包括细的粉质土和最多64%的留在75-m (200号)筛的砂和砾石组成的混合物（5.2.1）。这些占优势的粉质土壤很常见。从亚砂土到亚黏土其特征发生变化。其作为路面成分时在正确的含水量下可以表现良好。然而它们常常具有亲水性并会膨胀而失去稳定性，除非被适当地碾压和排水。此外其易于冻胀。这些土不易排水并可通过毛细作用吸水从而导致丧失强度。亚砂土常常难以被适当碾压。为了适当碾压，通常需要现场细心的含水量控制和气胎式压路机。Group A-5: The typical material of this group is similar to that described under Group A-4, except that it is usually of diatomaceous or micaceous character and may be highly elastic as indicated by the high liquid limit (5.2.2). These soils do not occur as widely as the A-4 soils. They are normally elastic or resilient in both the damp and semi-dry conditions. They are subject to frost heave, erosion, and loss of stability if not properly drained. Since these soils do not drain readily and may absorb water by capillary action with resulting loss in strength. Careful control of moisture content is normally required for proper compaction.组A-5：该组的典型材料类似于组A-4所描述的，此外当显示出高液限时通常具有硅藻的或云母质特征且可以是高度弹性的（5.2.2）。这些土壤不象A-4土壤那样广泛出现，在潮湿或半干状态下都常具有弹性。如未恰当排水则易于冻胀、冲蚀并丧失稳定性。这些土不易排水并可通过毛细作用吸水从而导致丧失强度。为了适当碾压，通常需要仔细控制含水量。Group A-6: The typical material of this group is plastic clay soil usually having 75 percent or more passing the 75-m (No. 200) sieve. The group includes also mixtures of fine clayey soil and up to 64 percent of sand and gravel retained on the 75-m (No. 200) sieve. Materials of this group usually have high volume change between wet and dry states (5.2.3). These soils are quite common in occurrence and are widely used in fills. When moisture content is properly controlled, they compact quite readily with either a sheepsfoot or pneumatic tired roller. They have high dry strength but lose much of this strength upon absorbing water. The A-6 soils will compress when wet and shrink and swell with changes in moisture content. When placed in the shoulders adjacent to the pavement, they tend to shrink away from the pavement edge upon drying and thereby provide an access route to the under side of the pavement for surface water. The A-6 soils do not drain readily and may absorb water by capillary action with resulting loss in strength.组A-6：该组的典型材料是塑性的黏土，通常具有通过75-m (200号)筛含量大于等于7