'T1 ROA! =HODS OF D'aLRIMNG ATTERICRO LIRITS0

Abstract

Atterberg limits define those moisture contents which designate the transition between the fluid and the plastic state and between the plastic and semi-solid state of a soil respectively. The main objection governing the design of any arbitrarily. selected device for measuring these limits is to eliminate the human factor in the accuracy of result and to ensure accurate duplication of results when tests are repeated. The conventional liquid limit test is essentially a dynamic shear test which does not provide a uniform basis for comparison of fine-grained soils as they differ in their behaviour when subjected to shaking test. The test becomes difficult for soils of lav plasti,pity and is significantly affected by minor differences in apparatus and procedure. This investigation is an attempt to overcome these difficul-ties. A 6)0 cone penetrometer has been developed for deter-mining liquid limit of soil with a view to extend it further for shear strength measurement of soils. The conventional plastic limit test is greatly affected by the operator's technique and often does not give reproducible results of plastic limit for °oils of lc77 plasti- city. this investigation* new cube method is propocod for plastic limit which reduces the effect of operator's technique and gives relatively reproducible results for soils of low plasticity.