Unified Soil Classification System

2
referenced documents
ASTM Standards includ C1 17 D420 D653 and so on.
3
terminology
some terminology such as clay gravel silt and except a s listed in D2487,all definiti ons are in accordance with Terminology D653.
how to classify by the USCS
GROUP SYMBOL
CL(低塑性黏土）、CL-ML（低塑性黏土~低塑 性粉土）、OL（低塑性有机土）、MH（高塑性、 粉土）、OH（高塑性有机土）· · ·
GROUP NAME
lean clay 、lean clay with gravel、silty clay、gravelly silty clay.
4
summary
this classification system i dentifies three major soil di visions: coarse-grained soil s,fine-grained soils,and hig hly organic soils.These thre e divisions are further subd ivided into a total of 15 basi c groups.
some charts we should know
some charts we should know
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5
signification and use
representing the results of prescribed laboratory tests to dertermine the particle-si ze characteristics, the liqui d limit, and the plasticity in dex.
Company name
Unified Soil Classification System
目录
CONTENTS
scope
1
4
summary
referenced documents
2
3
5
signification and use
terminology
1
scope
describes a system for clas sifying mineral and organomineral soils for engineerin g purposes.
Biblioteka Baidu
how to name soils by group symbol and group name
For example,how to make sure silty clay with sand (砂性粉质 黏土）is itself.
First,check how much the soil passes NO.200 Sieve.It should 50% or more,called Fine-Grained Soil.Then check LL(液限），it should < 50%.After that, check whether it is inorganic( (LL-overdried)/(LL-not dried)>=0.75),then check PI,PI should be between 4~7.it is in the CL~ML.Then it should <30% plus NO.200.Next,it should be 15-29% plus NO.200.Finally if content of sand is more than the content of gravel,we can make sure that this soil should be silt clay with sand.