Effect of Geofoam on Vertical Stress Distribution on Buried Structures Subjected to Static and Cyclic Footing Loads

Al-Naddaf, Mahdi; Han, Jie; Xu, Chao; Rahmaninezhad, S. Mustapha

doi:10.1061/(asce)ps.1949-1204.0000355

Cited by 38 publications

(8 citation statements)

References 23 publications

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“…For these reasons it has been used in a range of geotechnical applicationse.g. in embankment construction, over pipes and in culvert and other retaining walls (Duškov 1997;Zou et al 2000;Zarnani and Bathurst 2007;Vaslestad et al 2008;Farnsworth et al 2008;Hatami and Witthoeft 2008; Barrett and Valsangkar 2009;Horvath 2010;Newman et al 2010;Bartlett et al 2015;Witthoeft and Kim 2015;Meguid et al 2017a,b;Al-Naddaf et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Experimental Evaluation of Geocell and EPS Geofoam as Means of Protecting Pipes at the Bottom of Repeatedly Loaded Trenches

et al. 2020

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With growing populations and continuing urban development, embedding pipes in the ground that are then over-run by traffic is inevitable. This paper describes full-scale prototype tests on high-density polyethylene (HDPE) flexible pipes (of 250 mm diameter), buried at shallow depth, under simulated traffic loading. The paper studies the effect of surface load diameter (0.6×, 0.8× and 1× pipe diameter) and the amplitude of repeated load (400 or 800 kPa) on pipe behavior. The effects of EPS (expanded polystyrene) geofoam block of various densities and also of geocell as a 3D reinforcement, in reducing the pressure transferred to the pipe, the deformation of the pipe and the surface settlement of the backfill were investigated.The results show that, with increase in loading surface diameter, the pipe's vertical diametral strain, the pressure transferred to the pipe and the surface settlement grow significantly, irrespective of applied pressure. Using an EPS block over the pipe, increases the soil settlement but reduces transferred pressure onto the pipe and, consequentially, results in lower pipe deformations. The increase in density of an EPS block helps improve response, but was still found to be insufficient to prevent increase in surface deflections. The use of geocell reinforcement beneath the loading surface not only reduces the pressure transferred to the pipe and decreases its deformation, but also significantly negates the tendency of the EPS block to increase the soil surface settlement.Thus, a geocell reinforcement layer placed over two EPS geofoam blocks (with a total thickness 0.3×, and width 1.5×, the pipe diameter) all above a pipe buried at a depth of twice pipe diameter, was found to deliver acceptable, stable response. By these means, the vertical pipe strain, transferred pressure over the pipe and soil surface settlement were reduced, respectively, by 0.45, 0.37 and 0.53× those obtained for the comparable unmodified buried pipe installation, and are within allowable limits.

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Section: Introductionmentioning

confidence: 99%

Experimental Evaluation of Geocell and EPS Geofoam as Means of Protecting Pipes at the Bottom of Repeatedly Loaded Trenches

et al. 2020

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“…to criticism in its own regard; Sladen and Oswell (1988) (Meguid et al, 2017a;Meguid et al, 2017b;Meguid and Hussein, 2017). Additional reduced-scale model tests have been used to evaluate the effectiveness of EPS geofoam in induced trench construction (Al-Naddaf et al, 2019;Ma et al, 2019), and the feasibility of using thin geocomposite material in place of the traditional compressible zone has also been explored (Plácido and Portelinha, 2019). Ni et al (2018) performed numerical analyses assessing the effectiveness of tire derived aggregate (TDA) in induced trench construction, while Mahgoub and El Naggar (2019) used two full-scale test-sites to investigate the benefits of installing TDA above pre-existing buried structures.…”

Section: -11-07mentioning

confidence: 99%

The mechanics of arching in induced trench construction – a new theoretical formulation

2022

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Full-scale experimental case studies have shown that the induced trench construction method effectively reduces the vertical earth load that is exerted on culverts installed beneath high embankments. Induced trench culverts are traditionally designed on the basis of Marston’s theory; however, various theoretical shortcomings of this formulation have recently come to light. In this paper, a new induced trench theoretical formulation is presented. The proposed analytical model employs inclined shear planes within the embankment fill; such geometry is consistent with experimental findings reported in the literature, and leads to positive arching resulting from a reduction in vertical stress and an increase in horizontal stress (thus increasing the lateral earth pressure coefficient within the induced trench zone). A series of parametric studies are performed using finite element software. The proposed theoretical formulation is shown to be in good agreement with the numerical results, and correlations are developed to provide guidance in selecting the appropriate values of: 1) the induced trench lateral earth pressure coefficient, and 2) the height to the plane of equal settlement. Two instrumented full-scale induced trench case studies are discussed, and the proposed theoretical formulation is shown to produce results that are in good agreement with the experimental data.

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“…The mixture of air foam, natural clay and cement is called “lightweight cement clay” or “air cement mixed clay”. Lightweight cement clay has been widely used in transportation infrastructures such as embankments construction, airport, canal linings, bridges construction and underground engineering [12,13,14,15,16,17]. Thus, how to use these soft marine clays is related to an environmental problem for the sustainable development in civil engineering.…”

Section: Introductionmentioning

confidence: 99%

Physical and Mechanical Properties of a Bulk Lightweight Concrete with Expanded Polystyrene (EPS) Beads and Soft Marine Clay

Wang

Soon

2019

Materials

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The variation of physical and mechanical properties of the lightweight bulk filling material with cement and expanded polystyrene (EPS) beads contents under different confining pressures is important to construction and geotechnical applications. In this study, a lightweight bulk filling material was firstly fabricated with Singapore marine clay, ordinary Portland cement and EPS. Then, the influences of EPS beads content, cement content, curing time and confining pressure on the mass density, stress–strain behavior and compressive strength of this lightweight bulk filling material were investigated by unconsolidated and undrained (UU) triaxial tests. In these tests, the mass ratios of EPS beads to dry clay (E/S) were 0%, 0.5%, 1%, 2%, and 4% and the mass ratios of cement to dry clay (C/S) were 10% and 15%. Thirdly, a series of UU triaxial tests were performed at a confining pressure of 0 kPa, 50 kPa, 100 kPa, and 150 kPa after three curing days, seven curing days, and 28 curing days. The results show that the mass density of this lightweight bulk filling material was mainly controlled by the E/S ratio. Its mass density decreased by 55.6% for the C/S ratio 10% and 54.9% for the C/S ratio 15% when the E/S ratio increased from 0% to 4% after three curing days. Shear failure more easily occurred in the specimens with higher cement content and lower confining pressure. The relationships between compressive strength and mass density or failure strain could be quantified by the power function. Increasing cement content and reducing EPS beads content will increase mass density and compressive strength of this lightweight bulk filling material. The compressive strength with curing time can be expressed by a logarithmic function with fitting correlation coefficient ranging from 0.83 to 0.97 for five confining pressures. These empirical formulae will be useful for the estimation of physical and mechanical properties of lightweight concretes in engineering application.

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Effect of Geofoam on Vertical Stress Distribution on Buried Structures Subjected to Static and Cyclic Footing Loads

Cited by 38 publications

References 23 publications

Experimental Evaluation of Geocell and EPS Geofoam as Means of Protecting Pipes at the Bottom of Repeatedly Loaded Trenches

Experimental Evaluation of Geocell and EPS Geofoam as Means of Protecting Pipes at the Bottom of Repeatedly Loaded Trenches

The mechanics of arching in induced trench construction – a new theoretical formulation

Physical and Mechanical Properties of a Bulk Lightweight Concrete with Expanded Polystyrene (EPS) Beads and Soft Marine Clay

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