Physical, chemical, and geotechnical properties of coal fly ash: A global review

The performance of a pavement depends on the quality of its subgrade and subbase layers; these foundational layers play a key role in mitigating the effects of climate and the stresses generated by traffic. Therefore, building a stable subgrade and a properly drained subbase is vital for constructing an effective and long lasting pavement system. This manual has been developed to help Iowa highway engineers improve the design, construction, and testing of a pavement system’s subgrade and subbase layers, thereby extending pavement life. The manual synthesizes current and previous research conducted in Iowa and other states into a practical geotechnical design guide [proposed as Chapter 6 of the Statewide Urban Design and Specifications (SUDAS) Design Manual] and construction specifications (proposed as Section 2010 of the SUDAS Standard Specifications) for subgrades and subbases. Topics covered include the important characteristics of Iowa soils, the key parameters and field properties of optimum foundations, embankment construction, geotechnical treatments, drainage systems, and field testing tools, among others.

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1051&context=intrans_reports

Design Guide for Improved Quality of Roadway Subgrades and Subbases

Retaining walls are critical geotechnical assets and their performance needs to be monitored in accordance to transportation asset management principles. Current practices for retaining wall monitoring consist mostly of qualitative approaches that provide limited engineering information or the methods include traditional geodetic surveying, which may provide high accuracy and reliability, but is costly and time-consuming. This study focuses on evaluating failure modes of a 2.43 m × 2.43 m retaining wall model using three-dimensional (3D) photogrammetry as a cost-effective quantitative alternative for retaining wall monitoring. As a remote sensing technique, photogrammetry integrates images collected from a camera and creates a 3D model from the measured data points commonly referred to as a point cloud. The results from this photogrammetric approach were compared to ground control points surveyed with a total station. The analysis indicates that the accuracy of the displacement measurements between the traditional total station survey and photogrammetry were within 1–3 cm. The results are encouraging for the adoption of photogrammetry as a cost-effective monitoring tool for the observation of spatial changes and failure modes for retaining wall condition assessment.

/pdf/a-novel-application-of-photogrammetry-for-retaining-wall-3ldzdlj93r.pdf

A Novel Application of Photogrammetry for Retaining Wall Assessment

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http://www.fp.utm.my/epusatsumber/pdffail/ptkghdfwP2/Lee%20Mei%20Yun.TP.pdf

Declaration of thesis / undergraduate project paper and copyright

Today, as structures with life expectancy of more than 100 years are being constructed, it is vital to gain knowledge about the gradual decline in material properties. Accordingly, to ensure the longevity and safety of these structures, monitoring has been incorporated as a fundamental part of their service life. To monitor structural deformation, various methods have been developed, with the most common being the survey of certain points of a structure during and after construction using a total station. New techniques are now being developed, and one of the most promising ones is photogrammetry because it provides a simple method to monitor a structure using unmanned air vehicles (UAVs). This paper is aimed at sharing the strategic steps followed in monitoring the deflection of a simple secant pile retaining wall during excavation and construction of a basement. The monitoring is performed using a commercial UAV in combination with point cloud formation, georeferencing, and comparison software (cloud compare, I-Site Studio, 3D Reshaper, etc.). The monitoring results show very good agreement with the traditional inclinometer deflection measurements and numerical analysis, thereby demonstrating the feasibility of the proposed method. The authors believe that in the future, photogrammetry using UAVs can become the standard method for geotechnical monitoring because of its speed, lower cost and ease of use, when compared to conventional methods, a non-destructive method, and is easy to learn and use.

Aerial Close-Range Photogrammetry to Quantify Deformations of the Pile Retaining Walls

The purpose of this book is twofold: (1) To serve as a textbook for architectural and engineering students in undergraduate and graduate level courses, and (2) To serve as a reference for architectural and engineering practitioners The following chapters are included: (1) Classification of Soils; (2) Physical Properties of Soils; (3) Subsurface Soil Exploration; (4) Allowable Soil Bearing Pressure; (5) Spread Footings; (6) Piles, Piers and Caissons; (7) Lateral Earth Pressure; (8) Walls--Construction Details; (9) Walls--Design Considerations; (10) Soil Compaction; (11) Expansive Clay; and (12) Characteristics of Rock Appendices address the following: (A) Earth Pressure Transfer at Cold Joint by Shear-Friction; (B) Earth Pressure Transfer at Cold Joint by Shear Key; (C) Pressure Distribution within a Soil Mass; (D) Basement Slab on Ground--Empirical Design; (E) Dowels for Load Transfer into Footings; and (F) Buoyancy An Index is provided

Duncan

Papers

Soils and foundations for architects and engineers