The Experts below are selected from a list of 1467 Experts worldwide ranked by ideXlab platform

John S Horvath - One of the best experts on this subject based on the ideXlab platform.

  • framework for design guideline for expanded polystyrene block geofoam in slope stabilization and repair
    Transportation Research Record, 2010
    Co-Authors: David Arellano, John Benjamin Tatum, John S Horvath, Timothy D Stark, Dov Leshchinsky
    Abstract:

    This paper presents the framework for the interim design guideline for the use of expanded polystyrene (EPS) block geofoam for slope stabilization and repair, based on the findings of the NCHRP Project 24-11(02) Phase I study. The overall objective of this research is to develop a design guideline as well as an appropriate material and construction standard for the use of EPS block geofoam for the function of Lightweight Fill in slope stability applications. The recommended design methodology included in the framework is based on an assessment of the existing technology and literature. The Phase II work will refine the interim design guideline framework and address some uncertainties in the current state of the practice of analyzing various failure mechanisms included in the design procedure. The completed research will consist of the following five primary research products: (a) a summary of the relevant engineering properties, (b) a comprehensive design guideline, (c) a material and construction standard, (d) economic data, and (e) a detailed numerical example. No formal design guidelines on the use of any type of Lightweight Fill for slope stabilization by reducing the driving forces are available. Therefore, the proposed interim design guideline for EPS block geofoam can serve as a blueprint for the use of other types of Lightweight Fills in slope stability applications. The NCHRP Project 24-11(01) and the Project 24-11(02) Phase I research confirmed that EPS block geofoam is a unique Lightweight Fill material and can provide a safe and economical solution for slope stabilization and repair.

  • lateral pressure reduction on earth retaining structures using geofoams correcting some misunderstandings
    Earth Retention Conference (ER) 2010, 2010
    Co-Authors: John S Horvath
    Abstract:

    Block-molded expanded polystyrene and related geofoam materials can reduce lateral pressures acting on a wide variety of earth-retaining structures to almost zero under both gravity and seismic loading. There are two distinctly different functional ways to achieve this: Lightweight Fill and compressible inclusion. This paper updates the state of knowledge in this area with an emphasis on seismic buffers. This particular application, which makes use of the compressible-inclusion function, has seen increasing research interest in recent years. However there appear to be significant misunderstandings about material behavior that require clarification.

  • seismic lateral earth pressure reduction on earth retaining structures using geofoams
    Geotechnical Earthquake Engineering and Soil Dynamics Congress IV, 2008
    Co-Authors: John S Horvath
    Abstract:

    Geofoam is a type of cellular geosynthetic that can be used to reduce lateral earth pressures acting on a wide range of earth-retaining structures (ERSs). There are two distinct geosynthetic-functional ways in which geofoams can provide this benefit: as Lightweight Fill and as a compressible inclusion. These functions can be implemented either in new construction or retroactively with existing ERSs. Depending on the specific design details chosen, it is possible to reduce lateral earth pressures acting on an ERS to almost zero under both gravity and seismic loading. Unfortunately, the existence and capabilities of this geotechnology, which has the potential to revolutionize the way ERSs are designed, are still not widely known and thus have been significantly underutilized to date. This paper summarizes the state of knowledge concerning the use of geofoams to reduce lateral earth pressures on ERSs and addresses both analytical methods (with an emphasis on seismic loading) as well as geofoam materials and products. It is hoped that this will encourage both usage and research of this intriguing geotechnology.

An Deng - One of the best experts on this subject based on the ideXlab platform.

  • SUBMITTED VERSION Granular Lightweight Fill Composed of Sand and Tire Scrap
    2020
    Co-Authors: An Deng, Jinrong Feng, Xiong Zhang, Jie Zhang
    Abstract:

    ABSTRACT: A granular Lightweight Fill was proposed by blending sands with tire scrap in proportions. To research its deformation behavior helps understand its mechanical properties and determine the ground settlement in the fields. A laboratory investigation was conducted to disclose the materials' compression and shear deformation behaviors. Three tests were implemented, i.e., 1-D compression tests, direct shear tests and consolidated drained triaxial compression tests. A compression strain-load model was proposed to describe its compression behavior. Rebound-reload tests revealed that materials' plastic deformation was associated with the mixing ratios. The materials' shear stress-shear displacement curves were simulated using a hyperbolic model. Deviatoric stress-axial strain-volumetric strain curves were observed. Lightweight Fills underwent contraction during shearing process, which is different from the shear dilation behavior of compact sands. Effects of mixing ratios and stress conditions on shear deformation behaviors were also discussed. The efforts described in the paper not only provide technical data usable for deformation analyses, but also prompt the reuse of disposed tires to engineering domains

  • granular Lightweight Fill composed of sand and tire scrap
    GeoHunan International Conference: Challenges and Recent Advances in Pavement Technologies and Transportation GeotechnicsAmerican Society of Civil Eng, 2009
    Co-Authors: An Deng, Jinrong Feng
    Abstract:

    A granular geomaterial, known as sand-tire Lightweight Fill, was proposed by blending sand with disposed tire scrap in proportions. The geomaterial can be used as alternative backFill in many infrastructure works, where less overburdens and lateral loads are expected. The reuse of tire scraps may not only address growing environmental and economic concerns, but also help solve geotechnical problems associated with low soil shear strength. In this study, an experimental testing program was undertaken with the goal of evaluating the compression and shear behavior of the materials. Three tests were implemented, i.e., 1-D compression tests, direct shear tests and consolidated drained triaxial compression tests. A compression strain-load model was proposed to describe its compression behavior. Rebound-reload tests revealed that materials’ plastic deformation was associated with the mixing ratios. The tire scrap content was found to influence the stress-strain and volumetric strain behavior of the mixtures. Mixtures underwent shear contraction during shearing processes, which is different from the shear dilation of compact sands. Effects of mixing ratios and stress conditions on shear deformation behaviors were also discussed.

  • effect of different mixing ratios of polystyrene pre puff beads and cement on the mechanical behaviour of Lightweight Fill
    Geotextiles and Geomembranes, 2006
    Co-Authors: An Deng
    Abstract:

    Abstract A laboratory study on the formation of a Lightweight Fill material by blending soil with polystyrene pre-puff (PSPP) beads and other binders such as cement is presented in this paper. The effects of different compositions and different ratios between PSPP beads and soil, cement and soil, water and soil on the density, unconfined compressive strength and deformation of the Lightweight Fill formed are studied. It is observed that the density of the Lightweight Fill can be effectively controlled by the amount of PSPP beads used in making the Fill. With the inclusion of merely 2–6% of PSPP beads (to soil by weight), the density of the Lightweight Fill formed can be reduced to 700–1100 kg/m3. The shear strength and stiffness of the Lightweight Fill can be controlled by adjusting the amount of cement used. The unconfined compressive strength of the Lightweight Fill increases considerably if a cement to soil ratio of 10–15% is used. Compared with the expanded polystyrene (EPS) block geofoam, the PSPP beads mixed Lightweight Fill has a higher density, but higher shear strength and higher stiffness too. It can be used as a substitute of EPS blocks when irregular shaped volumes are to be Filled or when stronger Fill materials are required.

David Arellano - One of the best experts on this subject based on the ideXlab platform.

  • framework for design guideline for expanded polystyrene block geofoam in slope stabilization and repair
    Transportation Research Record, 2010
    Co-Authors: David Arellano, John Benjamin Tatum, John S Horvath, Timothy D Stark, Dov Leshchinsky
    Abstract:

    This paper presents the framework for the interim design guideline for the use of expanded polystyrene (EPS) block geofoam for slope stabilization and repair, based on the findings of the NCHRP Project 24-11(02) Phase I study. The overall objective of this research is to develop a design guideline as well as an appropriate material and construction standard for the use of EPS block geofoam for the function of Lightweight Fill in slope stability applications. The recommended design methodology included in the framework is based on an assessment of the existing technology and literature. The Phase II work will refine the interim design guideline framework and address some uncertainties in the current state of the practice of analyzing various failure mechanisms included in the design procedure. The completed research will consist of the following five primary research products: (a) a summary of the relevant engineering properties, (b) a comprehensive design guideline, (c) a material and construction standard, (d) economic data, and (e) a detailed numerical example. No formal design guidelines on the use of any type of Lightweight Fill for slope stabilization by reducing the driving forces are available. Therefore, the proposed interim design guideline for EPS block geofoam can serve as a blueprint for the use of other types of Lightweight Fills in slope stability applications. The NCHRP Project 24-11(01) and the Project 24-11(02) Phase I research confirmed that EPS block geofoam is a unique Lightweight Fill material and can provide a safe and economical solution for slope stabilization and repair.

  • a framework for the design guideline for eps block geofoam in slope stabilization and repair
    2010
    Co-Authors: David Arellano, John Benjamin Tatum, Timothy D Stark
    Abstract:

    This paper presents the framework for the interim design guideline for the use of expanded polystyrene (EPS)-block geofoam for slope stabilization and repair based on the National Cooperative Highway Research Program (NCHRP) Project 24-11(02) Phase I study. The overall objective of this research is to develop a design guideline as well as an appropriate material and construction standard for the use of EPS-block geofoam for the function of Lightweight Fill in slope stability applications. The recommended design methodology included in the framework is based on an assessment of existing technology and literature. The Phase II work will refine the interim design guideline framework and address some uncertainties in the current state-of-practice of analyzing various failure mechanisms included in the design procedure. The completed research will consist of the following five primary research products: (1) summary of relevant engineering properties, (2) a comprehensive design guideline, (3) a material and construction standard, (4) economic data, and (5) a detailed numerical example. Currently, no formal design guidelines to use any type of Lightweight Fill for slope stabilization by reducing the driving forces are available. Therefore, the proposed interim design guideline for EPS-block geofoam can serve as a blueprint for the use of other types of Lightweight Fills in slope stability applications. The NCHRP Project 24-11(01) and the Project 24-11(02) Phase I research confirmed that EPS-block geofoam is a unique Lightweight Fill material and can provide a safe and economical solution for slope stabilization and repair. Arellano, Tatum, Stark, Horvath, Leshchinsky 3

  • preliminary design procedure for eps block geofoam Lightweight Fill in levees overlying soft ground
    2010
    Co-Authors: David Arellano
    Abstract:

    Construction of levees on soft foundation soils, such as peats or soft clays, has long been problematic. Two main approaches for coping with the problem are (1) to improve the engineering properties, e.g., shear strength and compressibility, of the foundation soils or (2) to reduce the weight of the levee and thus the load applied to the soft foundation soils. The use of expanded-polystyrene (EPS)-block geofoam for the function of Lightweight Fill is one alternative to reducing the weight of the levee. Despite several case histories reported in the literature of EPS-block geofoam levees, EPS-block geofoam levees overlying soft ground are not currently extensively used internationally and in U.S. practice because comprehensive design guidelines have been unavailable. Therefore, there is a need in the U.S. to develop a detailed design guideline for the use of EPS-block geofoam in levees in routine practice. In an effort to address this need, this paper presents a proposed framework for developing a comprehensive design guideline for the use of expanded-polystyrene (EPS)-block geofoam for levee construction over soft ground. The basis of the proposed framework is the guideline for geofoam applications in highway embankments that was published in the National Cooperative Highway Research Program (NCHRP) Report 529 and the current ongoing NCHRP design guideline work for the use of EPS-block geofoam in slope stabilization and repair.

Dov Leshchinsky - One of the best experts on this subject based on the ideXlab platform.

  • framework for design guideline for expanded polystyrene block geofoam in slope stabilization and repair
    Transportation Research Record, 2010
    Co-Authors: David Arellano, John Benjamin Tatum, John S Horvath, Timothy D Stark, Dov Leshchinsky
    Abstract:

    This paper presents the framework for the interim design guideline for the use of expanded polystyrene (EPS) block geofoam for slope stabilization and repair, based on the findings of the NCHRP Project 24-11(02) Phase I study. The overall objective of this research is to develop a design guideline as well as an appropriate material and construction standard for the use of EPS block geofoam for the function of Lightweight Fill in slope stability applications. The recommended design methodology included in the framework is based on an assessment of the existing technology and literature. The Phase II work will refine the interim design guideline framework and address some uncertainties in the current state of the practice of analyzing various failure mechanisms included in the design procedure. The completed research will consist of the following five primary research products: (a) a summary of the relevant engineering properties, (b) a comprehensive design guideline, (c) a material and construction standard, (d) economic data, and (e) a detailed numerical example. No formal design guidelines on the use of any type of Lightweight Fill for slope stabilization by reducing the driving forces are available. Therefore, the proposed interim design guideline for EPS block geofoam can serve as a blueprint for the use of other types of Lightweight Fills in slope stability applications. The NCHRP Project 24-11(01) and the Project 24-11(02) Phase I research confirmed that EPS block geofoam is a unique Lightweight Fill material and can provide a safe and economical solution for slope stabilization and repair.

A Drescher - One of the best experts on this subject based on the ideXlab platform.

  • engineering properties of shredded tires in Lightweight Fill applications
    Transportation Research Record, 1994
    Co-Authors: David E Newcomb, A Drescher
    Abstract:

    It is estimated that approximately 240 million automobile and truck tires are discarded annually in the United States. Until recently, these have typically been disposed of in landFills and in tire stockpile sites where they pose potential safety and health problems as well as being unsightly. The latest use of shredded tires as Lightweight Fill material is encouraging, however, and the number of applications may grow provided that their engineering properties become more understandable and the quantifying parameters are known. Exploratory field and laboratory tests for determining the basic properties of shredded tires are reported in this paper. In the field tests, where large-size shreds were used, the effort necessary for compacting layers of shredded tires with a bulldozer was measured. In the laboratory tests, the compressibility of small-size shreds was investigated by means of a one-dimensional compression test. In addition, for both the large- and small-size shreds, their gradation, bulk density, porosity, and void ratio were determined. For comparison, wood chips were tested. The results show that the bulk density of shredded tires is between that of traditional granular Fills and wood chips. However, their compressibility and rebound are much higher than those of the latter material, which could lead to premature fatigue failure of hard surface pavements. The apparent anisotropy of a shredded tire mass may also cause errors in predicting pavement deflections by means of classical, elastic multilayer system analysis, which assumes material isotropy.

  • development of design guidelines for use of shredded tires as a Lightweight Fill in road subgrade and retaining walls
    1994
    Co-Authors: A Drescher, David E Newcomb
    Abstract:

    The use of shredded tires as a Lightweight Fill material over weak soil deposits is gaining popularity as a means of disposing a great quantity of an undesirable waste material in a beneficial manner. This report discusses the production, past applications, and properties of shredded tires with respect to their use in Lightweight Fills. Shredded tires have the advantages of low bulk density, high permeability, and insensitivity to the presence or state of moisture. However, they possess a high degree of compressibility, and they exhibit a degree of rebound a typical of materials normally used in Lightweight Fills (e.g., woodchips). Before using shredded tires in a Fill, one must consider the layer thickness of the shredded tires, the amount of overburden to be placed on the tires, the type of pavement surface, and the volume of heavy traffic expected to use the roadway. Because of the orientation of shredded tires after placement, the importance of anisotropy as a future research topic is discussed.