scholarly journals Modeling the Resilient Modulus Variation of In Situ Soils due to Seasonal Moisture Content Variations

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Kevin Gaspard ◽  
Zhongjie Zhang ◽  
Gavin Gautreau ◽  
Khalil Hanifa ◽  
Claudia E. Zapata ◽  
...  
Keyword(s):  
Moisture Content ◽  
Resilient Modulus ◽  
Optimum Moisture Content ◽  
Test Method ◽  
Large Scatter ◽  
Controlling Parameter ◽  
Base Course ◽  
The Relationship ◽  
Level 2

LTRC is conducting a research project to determine the seasonal variation of subgrade resilient modulus (MR) in an effort to implement PavementME. One objective of that project, which is presented in this paper, was to locally calibrate the Enhanced Integrated Climate Model’s (EICM Fenv) curve for seasonal subgrade MR changes. Shelby tube sampling was conducted on six different roadways to a depth of approximately 7.92 m beneath the shoulder pavement’s base course. The AASHTO T-99 MR test method was used on all samples with an additional eight specimens being tested with NCHRP 1–28A MR test method. Four soils from Louisiana which were not from the six roadways were also tested and included in the analyses. Once the MR tests were completed and plotted, it was noticed that there was a rather large scatter (R2 = −0.266) around the EICM Fenv curve. The authors hypothesized that this occurred due to the density differences between in situ and remolded specimens. Further analyses confirmed this hypothesis. LTRC developed a new method based on the EICM Fenv method to determine the relationship between changes in subgrade MR as a function of changes in moisture content with the in situ moisture content and MR used as the control. This method differs from the EICM Fenv in that the EICM Fenv uses optimum moisture content as the controlling parameter. The LTRC method can be used for design purposes as well as level 2 inputs into the EICM.

scholarly journals An analysis of the factors influencing the relationship between soil properties and optimum moisture content and the formulation of an abbreviated test method of determinig maximum dry density

1997 ◽  
Author(s):  
◽  
Anthony James Allinsin
Keyword(s):  
Moisture Content ◽  
Liquid Limit ◽  
Optimum Moisture Content ◽  
Test Method ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Strength And Durability ◽  
The Relationship ◽  
Standard Compaction

The strength and durability of any soil structure is dependent on the quality of the compaction of the soil. This quality is measured by employing a standard compaction test, which provides a standard with which density may be compared, called the maximum dry density, and the moisture content of the soil at which this is achieved, called the optimum moisture content. As a matter of routine during quality control, the particle size distribution, plasticity index and liquid limit of the soil are determined at the same time as its maximum dry density and optimum moisture content.

Model for predicting resilient modulus of unsaturated subgrade soil using soil-water characteristic curve

2015 ◽  
Vol 52 (10) ◽  
pp. 1605-1619 ◽  
Author(s):  
Zhong Han ◽  
Sai K. Vanapalli
Keyword(s):  
Moisture Content ◽  
Soil Water ◽  
Resilient Modulus ◽  
Characteristic Curve ◽  
Optimum Moisture Content ◽  
Model Parameters ◽  
Soil Water Characteristic Curve ◽  
Subgrade Soils ◽  
Fine Grained ◽  
Proposed Model

Soil suction (ψ) is one of the key factors that influence the resilient modulus (MR) of pavement subgrade soils. There are several models available in the literature for predicting the MR–ψ correlations. However, the various model parameters required in the existing models are generally determined by performing regression analysis on extensive experimental data of the MR–ψ relationships, which are cumbersome, expensive, and time-consuming to obtain. In this paper, a model is proposed to predict the variation of the MR with respect to the ψ for compacted fine-grained subgrade soils. The information of (i) the MR values at optimum moisture content condition (MROPT) and saturation condition (MRSAT), which are typically determined for use in pavement design practice; (ii) the ψ values at optimum moisture content condition (ψOPT); and (iii) the soil-water characteristic curve (SWCC) is required for using this model. The proposed model is validated by providing comparisons between the measured and predicted MR–ψ relationships for 11 different compacted fine-grained subgrade soils that were tested following various protocols (a total of 16 sets of data, including 210 testing results). The proposed model was found to be suitable for predicting the variation of the MR with respect to the ψ for all the subgrade soils using a single-valued model parameter ξ, which was found to be equal to 2.0. The proposed model is promising for use in practice, as it only requires conventional soil properties and alleviates the need for experimental determination of the MR–ψ relationships.

scholarly journals Measurement of Peat Soil Shear Strength Using Wenner Four-Point Probes and Vane Shear Strength Methods

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Irfan Ahmad Afip ◽  
Siti Noor Linda Taib ◽  
Kamaruzaman Jusoff ◽  
Liyana Ahmad Afip
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Soil Salinity ◽  
Peat Soil ◽  
Undrained Shear Strength ◽  
Soil Resistivity ◽  
In Situ Test ◽  
Soil Shear Strength ◽  
The Relationship

The general objective of this research was to measure the peat soil shear strength using Wenner four-point probes and vane shear strength methods. Specifically, the objective of this study was two-fold, namely, (a) investigating the relationship between laboratory soil resistivity and undrained shear strength and (b) determineing the relationship between in-situ soil resistivity and undrained shear strength. Data were randomly collected over six locations in Meranek, Sarawak, for in-situ test and three repetitions for each data were set based on three parameters. The selected parameters were soil density, moisture content, and salinity for both laboratory and in-situ test using Wenner four-point probes and vane shear method. The soil resistivity and vane shear strength readings for laboratory test were correlated with soil salinity, moisture content, and density. The R2 values showed a good correlation for soil salinity (R2 =0.8468) and density (R2 =0.9475), respectively. However, a weak correlation of R2 =0.1205 was observed for soil moisture. The R2 value for in-situ correlation between soil resistivity and three parameters (soil salinity, moisture content, and density) was R2 =0.8916. It can be concluded that the peat soil shear strengths of the study area using Wenner four-point probes from in-situ were (4.38 ohm.m) and laboratory was (2.47 ohm.m) and when using the vane shear strength method, in-situ was (23 kPA) and laboratory was (5 kPA). This study implies that the peat soil of the study area can be categorized as texture (soft loamy soil) and it is suitable for agriculture instead of construction. The relationship established between Wenner four-point probes and vane shear method can be beneficial for ground engineering design to enhance investigation on site suitability. Future work on DUALEM-421 technique should be emphasised for better subsurface exploration accuracy and resolve peat depth for an in-situ test.

Analysis of the Influence of Water Content on Shanxi Loess CBR and Rebound Module

2014 ◽  
Vol 919-921 ◽  
pp. 820-823
Author(s):  
Xi Rong Wu ◽  
Li Li Zhu
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Resilient Modulus ◽  
Test Methods ◽  
Shanxi Province ◽  
Influence Of Water ◽  
The Times ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

Selection of five typical loess in Shanxi Province, the paper adopt the indoor test methods to prepares the different compaction and different moisture content specimens which were used to test CBR value and rebound module, analyzes the impact of compactness and moisture content on the CBR value and resilient modulus and establishes the relationship of CBR and moisture content. The result shows that the level of moisture content has great impact on CBR value and rebound module. The CBR value is maximal under optimum moisture content and maximum degree of compaction condition. The times of compaction have little effect on the improvement of CBR with increasing water content. The relationship of the soaking CBR,resilient modulus and the moisture content shows a certain regularity.Key words: Loess filler;the CBR;resilient modulus;compactness;moisture content;relationship

Test method for determination of optimum moisture content of soil and maximum dry density

2015 ◽  
Vol 19 (7) ◽  
pp. 2061-2066 ◽  
Author(s):  
Xiao-Chuan Ren ◽  
Yuan-Ming Lai ◽  
Fan-Yu Zhang ◽  
Kai Hu
Keyword(s):  
Moisture Content ◽  
Optimum Moisture Content ◽  
Test Method ◽  
Dry Density ◽  
Maximum Dry Density

Study on the Relations of Strength Control Indicators of Road Subgrade in Shanxi Loess Region

2014 ◽  
Vol 919-921 ◽  
pp. 1160-1163
Author(s):  
Xi Rong Wu ◽  
Li Li Zhu
Keyword(s):  
Moisture Content ◽  
Key Words ◽  
Water Content ◽  
Test Section ◽  
Laboratory Experiments ◽  
Resilient Modulus ◽  
Poor Correlation ◽  
Bearing Plate ◽  
Loess Region ◽  
The Relationship

Typical loess areas of Shanxi test section as the basis, through on-site tests, the paper presents the relationship between filed CBR, compaction,moisture content and on-site bearing plate modulus. Through laboratory experiments, the paper examines the variation of resilient modulus and CBR in different water content and degree of compaction conditions. The correlation between site and interior strength indicators was analyzed and the result shows that indicators tested in laboratory have good correlation while indicators tested in field have poor correlation. Key words: loess; rebound modules; CBR; moisture content;compaction; correlation

Sign in / Sign up

Export Citation Format

Share Document