Laboratory Shear Strength Measurements of Municipal Solid Waste at Room and Simulated In Situ Landfill Temperature, Barmshoor Landfill, Iran

Shi

et al. 2022

Sci Rep

Due to rapid degradation of the newly filled municipal solid waste (MSW), the local temperature of the waste layer increases greatly. The mechanical parameters related to waste degradation and the deformation of high-density polyethylene (HDPE) pipes in the waste body will be affected by the elevated temperature. To predict the temperature distribution in the anaerobic landfill, a one-dimensional heat transfer model is established in this study. This model considers the stratification of the saturated and unsaturated zones, and the layering of new and old waste. Furthermore, a single peak model for heat production is applied as the source term of heat production. The stratification of the unsaturated and saturated zones is considered by distinguishing the difference in heat conductivity and specific heat capacity. The layering of the new and old waste layers is considered by distinguishing the difference in the length of time that waste has been degraded to produce heat. Based on the numerical calculation method, the temperature distribution in a landfill with layered new and old MSW is well simulated. The position where the maximum temperature occurs and the variation in the temperature at the edge of new and old waste are elucidated. The sensitivity analysis shows that the influence of the density on the temperature distribution is more significant. Besides, the stratification of saturated–unsaturated waste should also be considered in landfills.

Section: Introductionmentioning

confidence: 99%

Simulation of heat transfer in a landfill with layered new and old municipal solid waste

Shi

et al. 2022

Sci Rep

“…At present, there are three main methods for environmentally sound disposal of municipal solid waste (MSW): sanitary land ll, incineration, and composting. Sanitary land lls are the most frequently used to treat MSW (Wang et al 2015;Eskandari et al 2016;Falamaki et al 2018; Madon et al 2019), especially in developing and underdeveloped countries, owing to their economic and environmental bene ts (Reddy et al 2009;Falamaki et al 2019). As waste continues to be added to land lls, the height of the pile becomes increasingly steeper; the lack of su cient knowledge regarding the factors affecting the strength of MSW land lls (Zhu et al 2009; Guerrero et al 2013) has caused destabilization damage to occur in some areas.…”

Section: Introductionmentioning

confidence: 99%

Effects of moisture content and landfill age on the shear strength properties of municipal solid waste in Xi'an, China

Huang

Lan

et al. 2022

Preprint

As waste landfills continue to expand, accidents can occur if these landfills are not properly stabilized. In this study, samples of municipal solid waste (MSW) from a waste landfill in Xi'an, China were collected through on-site drilling. Considering the effects of eight landfill ages (1, 2, 3, 11, 12, 13, 21, 22, and 23 y) and six moisture contents (natural, 20, 40, 60, 80, and 100%), 324 groups of MSW were tested in the laboratory with a direct shear test apparatus. The results indicate the following: (1) with an increase in horizontal shear displacement, the shear stress of MSW gradually increases without a peak stress phenomenon, which is a displacement hardening curve; (2) with an increase in landfill age, the shear strength of MSW increases; (3) with an increase in moisture content, the shear strength of low-age MSW first increases and then decreases, but the relationship between shear strength and moisture content of medium- and high-age MSW is not significant; (4) with an increase in landfill age, the cohesion (c) decreases, and the internal friction angle (φ) increases; (5) with an increase in moisture content, the c and φ of low-age MSW first increases and then decreases. Based on these results, a shear strength, landfill age, and moisture content correlation model is established, and the model has a high degree of fit with the overall experimental data. The results of this study can provide a reference for the stability calculations of MSW landfills.

“…Many researchers (Landva and Clark 1990, Singh and Murphy 1990, Kavazanjian et al 1995, Gabr and Valero 1995, Manassero et al 1996, Jones et al 1997, Machado et al 2002, Stark et al 2009, Bray et al 2009, Reddy et al 2009a, Bareither et al 2012, Zhang et al 2014, Zekkos and Fei 2016, Abreu and Vilar 2017, Fei and Zekkos 2017, Falamaki et al 2019, Keramati et al 2020) conducted a shear strength test study on MSW, and conducted an instability failure simulation model analysis on an existing landfill. However, unlike MSW, research on the shear strength of MBT waste appears to be more limited.…”

Section: Introductionmentioning

confidence: 99%

Research on direct shear strength characteristics of mechanically biologically treated waste

Wang

et al. 2021

Environ Sci Pollut Res

Mechanically biologically treated (MBT) waste has significant characteristics such as high stability and low moisture content, which can reduce water, soil, and gas pollution in subsequent treatments. This pre-treatment method is environmentally friendly and sustainable, and has become a popular research topic in the field of environmental geotechnical engineering. Using a direct shear test apparatus and five shearing rates (0.25, 1, 5, 10, and 20 mm/min), the shear strength characteristics of MBT waste at the Hangzhou Tianziling (HT) Landfill were studied. The results indicate: (1). With the increase in horizontal shear displacement, the shear stress of MBT waste gradually increases without a peak stress phenomenon, which is a displacement hardening curve; (2). The shear strength increased with an increase in the shearing displacement rate, and the sensitivity coefficient was 0.64-2.66. (3). The shear strength, shearing rate, and normal stress correlation model are established, and the model has a high degree of fit with the overall experimental data; (4). Cohesion (c), internal friction angle (φ), and the logarithm of the shearing rate are linear; (5). The range of c of MBT waste is 22.32-39.51 kPa, and φ is 64.24-.68.52°. Meanwhile, the test data are compared with the test data in the literature, and the shear characteristics of HT-MBT waste are discussed. The research results of this study can provide a reference for the stability calculation of MBT landfills.