Effect of fiber reinforcement on triaxial shear behavior of cement treated sand

Laboratory Investigation on Strength Characteristics of Expansive Soil Treated with Jute Fiber Reinforcement

The purpose of this investigation was to identify and quantify the effect of numerous variables on the performance of fiber-stabilized sand specimens. Laboratory unconfined compression tests were conducted on sand specimens reinforced with randomly oriented discrete fibers to isolate the effect of each variable on the performance of the fiber-reinforced material. Five primary conclusions were obtained from this investigation. First, the inclusion of randomly oriented discrete fibers significantly improved the unconfined compressive strength of sands. Second, an optimum fiber length of 51 mm (2 in.) was identified for the reinforcement of sand specimens. Third, a maximum performance was achieved at a fiber dosage rate between 0.6 and 1.0% dry weight. Fourth, specimen performance was enhanced in both wet and dry of optimum conditions. Finally, the inclusion of up to 8% of silt does not affect the performance of the fiber reinforcement.

Closure of "Engineering Properties of Sand-Fiber Mixtures for Road Construction"

Suitability analysis for siting MSW landfills and its multicriteria spatial decision support system: method, implementation and case study.

Landfill site selection is a complex and time-consuming process, which requires evaluation of several factors where many different attributes are taken into account. Decision makers always have some difficulties in making the right decision in the multiple attribute environments. After identifying candidate sites, these sites should be ranked using decision-making methods. This study applies Chang’s fuzzy AHP-based multiple attribute decision-making (MADM) method for selection of the best site of landfills based on a set of decision criteria. The Fuzzy Analytic Hierarchy Process (FAHP) was designed to make pairwise comparisons of selected criteria by domain experts for assigning weights to the decision criteria. Analytic Hierarchy Process (AHP) is used to make pairwise comparisons and assign weights to the decision criteria. It is easier for a decision maker to describe a value for an alternative by using linguistic terms and fuzzy numbers. In the fuzzy-based AHP method, the rating of each alternative was described using the expression of triangular fuzzy membership functions. Once the global weights of the criteria is calculated by AHP, they are incorporated into the decision matrices composed by decision maker and passed to fuzzy-AHP method which is used to determine preference order of siting alternatives. In this study, a computer program based on the Chang’s fuzzy method was also developed in MATLAB environment for ranking and selecting the landfill site. As an example of the proposed methodology, four different hypothetical areas were chosen and implemented to demonstrate the effectiveness of the program. By using this program, the precision was improved in comparison with traditional methods and computational time required for ranking and selecting the suitable landfill site was significantly reduced.

Landfill site selection by decision-making tools based on fuzzy multi-attribute decision-making method

Soil reinforcement using discrete randomly distributed fibers has been widely investigated over the last 30 years. Several models were suggested to estimate the improvement brought by fibers to the shear strength of soils. The objectives of this paper are to (1) supplement the data available in the literature on the behavior of fiber-reinforced sands; (2) study the effect of several parameters which are known to affect the shear strength of fiber-reinforced sands; and (3) investigate the effectiveness of current models in predicting the improvement in shear strength of fiber-reinforced sand. An extensive direct shear testing program was implemented using coarse and fine sands tested with three types of fibers. Results indicate the existence of a fiber-grain scale effect which is not catered for in current prediction models. A comparison between measured and predicted shear strengths indicates that the energy dissipation model is effective in predicting the shear strength of fiber-reinforced specimens in reference to the tests conducted in this study. On the other hand, the effectiveness of the predictions of the discrete model is affected by the parameters of the model, which may depend on the test setup and the procedure used for mixing the fibers.

Shear Strength of Fiber-Reinforced Sands

The complex process of siting landfills involves a number of stakeholders with varying perspectives and priorities. The constraints which must be met by any potential landfill site are numerous and diverse. In this paper a GIS‐based decision‐aid tool and framework are presented as a robust alternative for analysing large sets of complex data of varying nature in a quick and reliable manner. The approach devised is flexible. It allows the siting criteria, the associated importance factors, and site compliance levels, to be easily varied by means of drop‐down menus embedded in ArcGIS, to reflect local and regional priorities and concerns. The case of Lebanon has been used to illustrate potential uses of the tool and methodology, which could be implemented in any other context for which the base data are available. The necessary data coverages were obtained and/or developed from Lebanese country‐wide sources, coupled with field surveys. Two basic scenarios were simulated for demonstration purposes: the first...

Compliance factors within a GIS‐based framework for landfill siting

Understanding the response of pile foundations to seismic loads is a necessary prerequisite to properly analyze and/or design them. This objective presents the civil engineering student and teacher with a complex problem, which typically challenges and strains the traditional didactic educational approach. In teaching the topic, we had faced significant difficulties in meeting the challenge of leaving the students with a thorough appreciation and understanding of the material. This was reflected in course evaluation results and comments. As such, an attempt was initiated to improve and enhance the learning/teaching process by incorporating a spreadsheetbased set of analysis/design tools with associated graphical representations. The approach described herein proved to be an effective and accessible method, according to the feedback solicited from students. In this paper, the basic background and available methods for the design of laterally loaded piles are presented along with the developed spreadsheet tool. Two design methods were included; one is a commonly used solution for laterally loaded piles; the other is a hybrid method which we compiled during the course of our work. The programming techniques and the methodologies adopted are also included. The Excel spreadsheets which were developed are presented along with illustrative examples.

Fadi Freiha

Papers

Shear Strength of Fiber-Reinforced Sands

Compliance factors within a GIS‐based framework for landfill siting

The Use of Spreadsheets for the Seismic Design of Piles