Truncated base mechanically stabilized earth walls are the MSE walls with narrow base excavation length and steep excavation slope designed to save construction cost while pushing the technological envelope of geosynthetic reinforcement development. A wall with truncated geometry of a narrow base length and steep excavation slope can significantly increase its base bearing pressure.
Proper structural design of pavement systems requires knowing the resilient modulus of the soil as this parameter is a proven predictor of the stress-dependent elastic modulus of soil materials under traffic loading. In addition, the R-value test is conducted using a device called a stabilometer, where the material's resistance to deformation is expressed as a function of the ratio of the transmitted lateral pressure to that of the applied vertical pressure. Both tests are expensive and time consuming; however, establishing accurate and reliable correlations between the test results and the soil's physical properties, in lieu of laboratory testing, can save a considerable amount of time and money in the analysis and quality control process. For these reasons, correlations are typically used for estimating the resilient modulus and R-value for soils. The variability of a given soil type in different regions and states requires developing modified and specific correlations for each state based on statistical analysis of the statewide soil data collected. The main goal of this research study was to develop correlations among R-value, Resilient modulus, and soil's basic properties for available AASHTO soil types in databases in Colorado.
This set of guidelines generally follows current practice in the Division for obtaining soil profiles and is intended to establish standardized procedures for use by the District Materials Sections in the performance of uniform and adequate soils investigations. It is not design manual. The recommendations presented herein are oriented toward the solution of such problems as pavement design, slope design, slope appearance, cost, landslides, embankment subsidence and settlement, excavation characteristics, expansive materials, drainage, and compaction characteristics. All of these problems are directly related to the character and distribution of soil and rock bodies both inside and out-side of the right-of-way, and to the influence of-surface and sub-surface water on these materials. With the proper amount and kind of samples and field information, the designers are provided with data denoting the types of materials to be encountered, the vertical and horizontal boundaries of the changes in these materials, and their strength and deformation characteristics. Adequate preliminary investigation will help prevent uneconomical over design and unforeseen failure resulting from under design.
