Effect of elevated temperature on solid waste shear strength and landfill slope stability

2020 ◽  
pp. 0734242X2095806
Author(s):  
Jianyong Shi ◽  
Shi Shu ◽  
Yingbo Ai ◽  
Zhaoqi Jiang ◽  
Yuping Li ◽  
...  
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Solid Waste ◽  
Safety Factor ◽  
Friction Angle ◽  
Slope Instability ◽  
Maximum Temperature ◽  
Triaxial Tests ◽  
Landfill Liner ◽  
Cooling Pipes

Slope instability occurs in landfills owing to increased internal temperatures. However, strength characteristic tests for solid waste (SW) and landfill slope stability (SS) calculations that consider temperature variations are scarce in the literature. In this study, we conducted triaxial tests on SW under a range of temperature conditions and proposed the circular slide method (CSM) for calculating SS in consideration of temperature effects. SW cohesion decreased linearly with increasing temperature, whereas the internal friction angle remained essentially unchanged. Our results showed that higher temperatures reduced the SW shear strength, changing the most dangerous sliding arc away from the slope toe. The landfill slope safety factor decreased by more than 20% with an increase of the maximum temperature from 20°C to 50°C. Reduction of the leachate level (LL) led to a decrease in the landfill high-temperature zone and the safety factor increased according to LL and temperature distribution. If cooling pipes are used to control the SW temperature, we recommend arranging the cooling pipes on the landfill liner. The proposed CSM can be used to analyse landfill SS.

scholarly journals Peningkatan Stabilitas Lereng pada Ruas Jalan Tawaeli – Toboli dengan Vegetasi/Bioengineering

2021 ◽  
pp. 23-32
Author(s):  
S.A. Wandira ◽  
A. Rahayu
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Safety Factor ◽  
Friction Angle ◽  
Soil Samples ◽  
Plant Roots ◽  
Soil Conditions ◽  
Mountainous Area ◽  
Stability Calculation ◽  
The Road

Tawaeli - Toboli is one of the road that often undergo landslide. Most of these roads are in a mountainous area with high steep slopes and poor soil conditions. The road conditions worsened, especially in rainy season resulting the citizen do not know anywhere that is prone to landslides such as in Km 16 to 17. The purpose of this study was to analyze slope stability using bioengineering methods, determine the shear strength of soil without plant roots and soil with plant roots and to determine the potential for landslides that will occur. Bioengineering is used to increase the strength of the soil, and stabilize slopes and reduce erosion on slopes. The slope stability calculation using the Bishop slice method. The calculating of safety factor analyzed using the Slope / W application and manually. Soil samples were taken from 3 (three) points and the soil strength parameters,  soil cohesion and friction angle, were obtained through laboratory testing. Tests were carried out using rootless and rooted soil samples. In addition, direct field observations were made to obtain slope angles and slope heights. The results showed that the parameters of soil shear strength, cohesion and friction angle increased with the presence of plant roots. The results of the slope stability analysis show that the conditions of the slope are stable at slope 1 (Km 16) and slope 3 (Km 17) with a safety factor greater than 1.5. While slope 2 (Km 16 +300) has the potential for landslides as a safety factor of less than 1.5. The use of bioengineering increases the safety factor to be greater than 1.5. The calculation of the value of the safety factor using the Slope / W program and the Bishop manual is not much different, but the calculation time with the Slope / W program is faster

Study on the Effects of the Rainwater Seepage on Slope Stability

2014 ◽  
Vol 580-583 ◽  
pp. 729-732
Author(s):  
Ju Sheng Xun ◽  
Xiang Tian Xu ◽  
Rui Qiang Bai
Keyword(s):  
Moisture Content ◽  
Slope Stability ◽  
Safety Factor ◽  
Slope Instability ◽  
Rain Intensity ◽  
Work Condition ◽  
Mountainous Regions ◽  
Bishop’S Method ◽  
Coulomb Criterion ◽  
Road Slope

The work condition of the highway, which is usually built in mountainous regions, is complex relative to the ordinary road. Slope instability accident caused by the seepage of rainwater usually occurred in the rainy season. The mechanism for seepage failure of slope was investigated by used the Mohr-Coulomb criterion and the principle of effective stress. The effect of rain intensity on slope stability was equivalently instead by the effect of moisture content on slope stability. The influence of moisture content on the safety factor of slope stability was further calculated according to the Bishop’s method. The degeneration of safety factor follow to the moisture content was presented in the percentage.

scholarly journals UNDRAINED SHEAR STRENGTH PARAMETERS OF SAPROCK FROM A WEATHERING PROFILE OVER PORPHYRITIC BIOTITE GRANITE AT KM 31 OF THE KUALA LUMPUR - KARAK HIGHWAY, PENINSULAR MALAYSIA

2021 ◽  
Vol 33 (2) ◽  
Author(s):  
John Kuna Raj
Keyword(s):  
Shear Strength ◽  
Friction Angle ◽  
Undrained Shear Strength ◽  
Triaxial Tests ◽  
Regression Analyses ◽  
Shear Strength Parameters ◽  
Weathering Profile ◽  
Strength Parameters ◽  
Zone Ii ◽  
Undrained Shear

Three broad zones can be differentiated at the weathering profile; an upper, 9.4 m thick, pedological soil (zone I), an intermediate, 31.7 m thick, saprock (zone II) and the bottom bedrock (zone III). The saprock (zone II) comprises gravelly silty sands that distinctly preserve the minerals, textures and structures of the original granite and can be separated into sub-zones II A, II B, II C, and II D, based on differences in preservation of relict structures and content of litho-relicts (core-boulders). To characterize the undrained strength of saprock, samples were collected from sub-zones II A, II B, II C and II D and their physical and soil index properties determined before unconsolidated undrained triaxial tests were carried out on remolded samples. Three to four individual samples from each sub-zone were compressed under confining pressures of 138 kPa, 207 kPa, 276 kPa and/or 345 kPa. Plots of pf = [(σ1 + σ3)/2] versus qf = [(σ1 - σ3)/2] were then used to calculate apparent cohesions of 41.9 kPa, 100.3 kPa, 76.1 kPa and 73.9 kPa, and friction angles of 32.2o, 28.1o, 26.6o and 27.8o, for the samples from sub-zones II A, II B, II C, and II D, respectively. Regression analyses show apparent cohesions to decrease with increasing clay contents, and degrees of saturation; features indicating the influence of negative pore water (or suction) pressures. Regression analyses also show apparent friction angle to increase with increasing sand contents; a feature attributed to greater inter-locking and resistance to displacement of these particles. It is concluded that the undrained shear strength parameters of saprock are characterized by an average apparent cohesion of 54.6 kPa, and friction angle of 30.5o; the parameters influenced by the degree of saturation as well as clay and sand contents.

scholarly journals Numerical Simulation Analysis of Slope Instability and Failure of Limestone Mine in Weibei

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Kuiming Liu ◽  
Hui Li ◽  
Shihui Pang ◽  
Meng Mi ◽  
Jianping Chen ◽  
...  
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Simulation Analysis ◽  
Slip Surface ◽  
Three Dimensional ◽  
Stable State ◽  
Vertical Displacement ◽  
Slope Instability ◽  
Shaanxi Province ◽  
Geological Disaster

Weibei area is the largest limestone resource area in Shaanxi Province, which is an important boundary to distinguish the climate difference between the south and the north of China, and also a significant ecological safety protection barrier in the northwest of China. The complex geological environment and harsh environment make the mining area have serious geological disaster hidden danger. Based on the site engineering geological data of typical limestone quarry slope in Weibei, this paper constructs a three-dimensional geological model, uses FLAC3D software to simulate excavation, and analyzes the stress and strain law of the quarry slope. SlopeLE software was used to analyze the safety factor of slope stability and the potential slip surface before and after taking reinforcement measures. The results show the following: (1) Limestone is the main rock component of the mine, followed by mudstone. The joint and fissure are developed, the rock mass is broken, and the hidden danger of engineering geological disaster is high. (2) There is a sliding trend in both sides during excavation, and the maximum vertical displacement is 2.1 cm. (3) If the slope is reinforced according to the design scheme, the slope stability safety factor will be increased from 1.062 to 1.203 in a stable state, which greatly improves the stability of the slope and provides a guarantee for human and financial resources.

Influence of Water Content on the Behavior of Partially Saturated Fouled Ballast

2016 ◽  
Author(s):  
Zhenning Yang ◽  
Carlton L. Ho ◽  
Richard Joy ◽  
Nandan C. Dabhade
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Modulus Of Elasticity ◽  
Coulomb Friction ◽  
Field Capacity ◽  
Friction Angle ◽  
Triaxial Tests ◽  
Strengthening Effect ◽  
Partially Saturated ◽  
Fouled Ballast

The water content of fouled ballast is important when considering the shear strength and deformability of the ballast, and therefore critical in evaluating whether the track is at risk of excessive deformations warranting a speed restriction order. Fouled ballast from northeastern United States was tested in the laboratory to assess changes in shear strength and deformability as a function of water content. X-ray fluorescence analysis determined that the fouling material was 95% by weight basalt in origin. No more than 5% of the fouling material could be attributed to the abraded concrete ties. The field capacity of the fouled ballast was measured to be at a water content of 10%. Freezing and thawing tests indicated that approximately 4% of mass loss could be expected as a result of 25 freeze/thaw cycles. 6-inch triaxial tests, TX-CIDC, were conducted on the ballast at water contents between dry and field capacity (10%). As the ballast was partially saturated, volume change was measured using circumferential string potentiometers. The water content had an influence on the shear strength and the modulus of elasticity of the fouled ballast. The Mohr-Coulomb friction angle decreased from 47.3° for the dry ballast to 42.5° for the field capacity ballast. The Mohr-Coulomb cohesion decreased from 3.38 psi to nearly zero with initial addition of water, but increased to 6.18 psi as the water content reached field capacity. This is likely attributable to changes in capillary tension of the partially saturated fouling material. The average shear strength, Mohr-Coulomb friction angle, Mohr-Coulomb cohesion, modulus of elasticity and Poisson’s Ratio all showed weakening and strengthening effect by addition of water.

Shear strength testing of intact and recompacted samples of municipal solid waste

2009 ◽  
Vol 46 (10) ◽  
pp. 1133-1145 ◽  
Author(s):  
Manoj K. Singh ◽  
Jitendra S. Sharma ◽  
Ian R. Fleming
Keyword(s):  
Shear Strength ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Effective Stress ◽  
Deformation Behaviour ◽  
Triaxial Compression ◽  
Large Diameter ◽  
Shear Behaviour ◽  
Triaxial Tests ◽  
Strength Testing

This paper presents results of shear strength testing of intact and recompacted samples of municipal solid waste (MSW). A method for in situ sampling of MSW from landfills using a push-in sampler was developed and used to obtain intact samples of MSW from a large municipal landfill. Shear strength testing of MSW was carried out using a large triaxial compression apparatus as well as a large direct shear apparatus. The results are presented in terms of cohesion intercept (c′) and angle of shearing resistance ([Formula: see text]) and are compared with those available in published literature. Based on these results and their favourable comparison with this literature, it can be concluded that meaningful shear strength parameters for MSW can be obtained using consolidated undrained triaxial tests on large-diameter intact and recompacted samples. A fairly consistent picture of the shear behaviour of MSW obtained from effective stress paths in triaxial tests appears to suggest that shear behaviour of MSW can be explained using the effective stress principle. It is suggested that recompacted samples could be used for obtaining reasonable estimates of c′ and [Formula: see text] for MSW; however, it may be necessary to use intact samples to establish the pre-failure deformation behaviour of MSW.

Numerical Study of Plastic Strains on Slope Instability

2012 ◽  
Vol 548 ◽  
pp. 363-366
Author(s):  
Mao Hu Wang ◽  
Zhen Liang Xu
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Safety Factor ◽  
Numerical Study ◽  
Limit Equilibrium ◽  
Strength Reduction ◽  
Slope Instability ◽  
Open Pit ◽  
Instability Criterion ◽  
Incremental Search

This article simulates an open pit slope stability using the ANSYS software, which is based on the finite element strength reduction theory, three kinds of slope instability criterion of the strength reduction method are applied to judge whether the slope is on the limit equilibrium state, the incremental search method is used to search the safety factor of the slope stability, and the results show that, the slope body damages when the plastic zone developed from the top to the bottom, in the numerical simulation the finite element iteration calculation didn’t just converge, the corresponding former level of reduction factor is the safety factor, This article can have a guiding significance on the safety production of the open-pit mine.

scholarly journals Shear Testing of the Interfacial Friction Between an HDPE Geomembrane and Solid Waste

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1672
Author(s):  
Luming Zhou ◽  
Zhende Zhu ◽  
Zhenpeng Yu ◽  
Cong Zhang
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Solid Waste ◽  
Rough Surface ◽  
Interfacial Shear Strength ◽  
Friction Angle ◽  
Interfacial Shear ◽  
Solid Wastes ◽  
Interfacial Friction ◽  
Industrial Solid Waste

High-density polyethylene (HDPE) geomembrane is often used as an anti-seepage material in domestic and industrial solid waste landfills. To study the interfacial shear strength between the HDPE anti-seepage geomembrane and various solid wastes, we performed direct shear tests on the contact interface between nine types of industrial solid waste or soil (desulfurization gypsum, fly ash, red mud, mercury slag, lead-zinc slag, manganese slag, silica fume, clay and sand) and a geomembrane with a smooth or rough surface in Guizhou Province, China. Friction strength parameters like the interfacial friction angle and the apparent cohesion between the HDPE geomembrane and various solid wastes were measured to analyze the shear strength of the interface between a geomembrane with either a smooth or a rough surface and various solid wastes. The interfacial shear stress between the HDPE geomembrane and the industrial solid waste increased with shear displacement and the slope of the stress-displacement curve decreased gradually. When shear displacement increased to a certain range, the shear stress at the interface remained unchanged. The interfacial shear strength between the geomembrane with a rough surface and the solid waste was higher than for the geomembrane with a smooth surface. Consequentially, the interfacial friction angle for the geomembrane with a rough surface was larger. The geomembrane with a rough surface had a better shear resistance and the shear characteristics fully developed when it was in full contact with the solid waste.

The Affecting Factors of Slope Stability Based on Orthogonal Design

2013 ◽  
Vol 690-693 ◽  
pp. 756-759 ◽  
Author(s):  
Zhao Rong Jiang ◽  
Le Hua Wang
Keyword(s):  
Slope Stability ◽  
Safety Factor ◽  
Rock Slope ◽  
Orthogonal Experiment ◽  
Orthogonal Design ◽  
Limit Equilibrium ◽  
Friction Angle ◽  
Affecting Factors ◽  
Good Test ◽  
Test Range

The orthogonal design can make sites in the test range uniformly distributed, which is introduced to slope sensitivity analysis, and can greatly reduce the test times and gets a good test effect.The paper takes the flood discharging tunnel import slope of Jinchuan hydropower station for example, which is a rock slope. This article selects the bulk density, internal friction angle, cohesion, earthquake acceleration four factors to design the orthogonal experiment, and the safety factor of the slope as a test indicators, using the simplified Bishop method of limit equilibrium theory to calculate the safety factor and analyses the slope sensitivity. The results show that the cohesion and earthquake acceleration are the most sensitive factors, and have a very significant impact on the slope stability.

Casagrande resistance envelopes for rock and rockfill slopes having circular slip surfaces

1988 ◽  
Vol 25 (1) ◽  
pp. 42-49
Author(s):  
L. D. Baikie
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Key Words ◽  
Safety Factor ◽  
Preliminary Design ◽  
Safety Factors ◽  
Slip Surfaces ◽  
Envelope Method ◽  
Tension Cracks ◽  
Nonlinear Shear

A series of Casagrande resistance envelopes are presented for use in the preliminary design and evaluation of uniform rock and rockfill slopes. The influence of tension cracks on the safety factors for such slopes is examined. A comparison is also made between the safety factors obtained using the resistance envelope method and those obtained using published stability charts for rockfill slopes having nonlinear shear strength envelopes. Key words: rock, rockfill, slope, stability, Casagrande resistance envelope, safety factor.

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