Air-filled porosity, plastic limit
, and soil strength
The geotechnical characterization tests included: (i) particle-size distribution (ABNT, 1984a); (ii) specific gravity of soil solids (ABNT, 1984d); (iii) liquid limit (ABNT, 1984b); and (iv) plastic limit
Another popular J-estimation method is the reference stress approach which adopts the plastic limit
load as the reference stress .
Therefore, as the absence of related investigation, the unified strength theory is adopted for plastic limit
load analysis of the shaft lining, which takes the effects of intermediate principal stress and SD effect of material on the material strength into account [7-9], and can be used to analyze the plastic limit
of the shaft lining which is verified by a case study.
In recent years, demand from downstream industries is driven mainly by government regulations like the Plastic Limit
Order and No Plastics Order.
and compaction characteristics of finegrained soils, Proceedings of the ICE-Ground Improvement 9(1): 17-22.
The associated laboratory tests were performed following the procedures outlined by the Technical Specifications of INVIAS (Colombian National Institute of Roads): INV E-125-07 (corresponding to ASTM D 4318-00) to determine liquid limit, INV E-126-07 (corresponding to ASTM D 4318-00) to determine plastic limit
, and INV E-122-07 (corresponding to ASTM D 2216-98) to determine water content.
The PI is the difference between the liquid limit and the plastic limit
of the soil and is a convenient representation of its plasticity characteristics.
The variations of liquid limit and plastic limit
with varying percentages of fly ash are shown in Figures 1 and 2.
The plastic limit
and plasticity index of the soil samples was obtained using ASTM D4318-10 as the basis of the study.
Thus, the Ishlinsky model describes the effect caused by reduction of the plastic limit
under repeated load by a force acting in the opposite direction before the plastic limit
is reached (the Bauschinger effect).
The plastic limit
and plasticity index were significantly high and the optimum moisture content was below plastic limit