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(Image: Attention!) The term “Relative Density” is used exclusively for non-cohesive soils.
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The volume ratio between the three phases is described by the following parameters: (Formula: Void ratio) (Formula: Porosity) (Formula: Degree of saturation) (Image: Soil void ratio) |
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The higher the pore volume in relation to the total volume, the lower the density. (Image: Density) Relative Density: D = (nmax – n) / (nmax – nmin) Density Index: lD = (emax – e) / (emax – emin) Compactability: lF = (emax – emin ) / e |
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Classification and Designation of Non-Cohesive Soils
Using the relative density D and the density index lD, it is possible to determine the compaction of a soil sample. (Table: Classification of non-cohesive soils according to density, N value and inner angle … |
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Proctor Compaction Test
Purpose: (Image: Manual proctor devices) |
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The Proctor Compaction Test (described in [[ASTM D7263]] and/or [DIN18127:2012]) is used to determine the influence of water content on the achievable density of a soil sample. Test Procedure:
Key Outcome: |
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Cohesive Soils and Water Content
State Transitions as Water Content Decreases:
Key Effects of Decreasing Water Content:
Consistency Limits of Soil (Atterberg Limits) The water … |
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The consistency (condition) of cohesive soil can be determined either in-situ (on-site) or in a laboratory. In-situ Test Method The soil condition is classified based on the following observations:
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Using the soil samples' water content at the liquid and plastic limits, wL and wP (Atterberg consistency limit), according to [[ASTM D4318-10]] and/or [DIN18122], and the natural water content w, the consistency index IC (or CI) can be calculated : (Formula: Consistency index) The consistency index is a numerical representation of the consistency of a soil. (Table: Consistency index IC and designation of the soil state of cohesive soils in accordance … |
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Soil Plasticity Definition: Plasticity The plasticity range lies between:
This range is further classified into three categories:
[DIN18122] (Image: Consistency band [Trian00]) |
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The state conditions of the plastic range are shown as numerical values in the table. The liquidity index IL = 1 - IC is also listed. (Table: Conditions in the plastic range [DIN18122]) |
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Purpose of the Plasticity Index (IP) The plasticity index helps to:
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Special classifications and designations for fine soils (silt and clay) subject to the liquid limit wL can be found in EN ISO 14688-2. [DINENISO14688:2018] (Table: Classification of fine soils subject to the liquid limit wL or plasticity index IP as per EN ISO 14688-2) |
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Feb 10, 2020 Soil explorations, that are to be carried out to the required extent and then to be appropriately evaluated, form the basis for the structural calculations of already existing, newly to be laid, or to be rehabilitated drains, sewers and associated structures by means of the open cut or trenchless method of construction.
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Feb 10, 2020 For the design of sloping or benching systems, the Occupational Safety and Health Administration (OSHA) classifies soils from excavation operations as presented in the table below. The soil classification, according to [[OSHA 29 CFR 1926 Subpart P App A]], are based on the definitions in whole or in part, the following; American Society for Testing Materials (ASTM) Standards D653-85 and D2488; The Unified Soils Classification System; The U.S. Department … |
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Feb 10, 2020 The table below presents the classification of non-cohesive soils for engineering purposes based on particle size, coefficient of uniformity (Cu) and coefficient of curvature (Cc) [[ASTM D2487-06]]. (Table: Non-cohesive soil classification as per ASTM D2487) |
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Feb 10, 2020 The following table presents classification of cohesive soils for engineering purposes based on particle size, coefficient of uniformity (Cu) and coefficient of curvature (Cc) [[ASTM D2487-06]]. Cohesive soils do not crumble, are hard to break up when dry and include clayey silts, sandy clays, silty clays, and clays. (Table: Cohesive soil classification as per ASTM D2487) |
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Feb 10, 2020 Organic soils are classified as per [[ASTM D2487-06]] according to the table below. (Table: Organic soil classification as per ASTM D2487) |
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Feb 10, 2020 Organic fine-grained soils have a 50% or more passing rate through a No.200 sieve. Organic clays and organic silts are soils that would be classified as clay or silt, except that their liquid limit values after oven drying is less than 75 % of their liquid limit value before oven drying [[ASTM D2487-06]]. The table below presents a classification of organic fine-grained soils (OL and OH). (Table: Classification of organic fine-grained soil (50% or … |
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Feb 10, 2020 A simpler differentiation is done in European standard [DINENISO14688:2004]. This standard differentiates soils based on soil type, designation and grain size. (Table: Soil type and grain size fractions as per EN ISO 14688-1) |
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Feb 10, 2020 The main aim of The American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration (FHWA) soil classification system is to have a system appropriate for highway sub-grade materials based on their performance. The AASHTO System has seven soil classes including A-1 to A-7. The soil is placed in the classes based on performance characteristics. A-1 is the highest and A-7 is the lowest. A-1 to A-3 are … |
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