Reinforcement Load and Compression of Reinforced Soil Mass under Surcharge Loading

2015 ◽  
Vol 141 (6) ◽  
pp. 04015017 ◽  
Author(s):  
Huabei Liu
Keyword(s):  
Soil Mass ◽  
Reinforced Soil ◽  
Surcharge Loading

Stability of a single tunnel in cohesive–frictional soil subjected to surcharge loading

2011 ◽  
Vol 48 (12) ◽  
pp. 1841-1854 ◽  
Author(s):  
Kentaro Yamamoto ◽  
Andrei V. Lyamin ◽  
Daniel W. Wilson ◽  
Scott W. Sloan ◽  
Andrew J. Abbo
Keyword(s):  
Upper Bound ◽  
Limit Analysis ◽  
Ground Surface ◽  
Soil Mass ◽  
Building Technology ◽  
Surcharge Loading ◽  
Large Size ◽  
Surcharge Load ◽  
The Stability ◽  
Frictional Soils

This paper focuses mainly on the stability of a square tunnel in cohesive–frictional soils subjected to surcharge loading. Large-size noncircular tunnels are quickly becoming a widespread building technology by virtue of the development of advanced tunneling machines. The stability of square tunnels in cohesive–frictional soils subjected to surcharge loading has been investigated theoretically and numerically, assuming plane strain conditions. Despite the importance of this problem, previous research on the subject is very limited. At present, no generally accepted design or analysis method is available to evaluate the stability of tunnels or openings in cohesive–frictional soils. In this study, a continuous loading is applied to the ground surface, and both smooth and rough interface conditions between the loading and soil are modelled. For a series of tunnel geometries and material properties, rigorous lower and upper bound solutions for the ultimate surcharge loading of the considered soil mass are obtained by applying recently developed numerical limit analysis techniques. The results obtained are presented in the form of dimensionless stability charts for practical convenience, with the actual surcharge loads being closely bracketed from above and below. As a handy practical means, upper bound rigid-block mechanisms for square tunnels have also been developed, and the obtained values of collapse loads were compared with the results from numerical limit analysis to verify the accuracy of both approaches. Finally, an expression that approximates the ultimate surcharge load of cohesive–frictional soils with the inclusion of shallow square tunnels has been devised for use by practicing engineers.

Soil Stresses on Carbon Steel Pipe Undergoing Uplift

2016 ◽  
Vol 835 ◽  
pp. 439-443
Author(s):  
Yuri D. Costa ◽  
Lucas S. Moraes ◽  
Carina L. Costa
Keyword(s):  
Carbon Steel ◽  
Relative Density ◽  
Numerical Study ◽  
Three Dimensional ◽  
Soil Mass ◽  
Steel Pipe ◽  
Surcharge Loading ◽  
Flexible Pipes ◽  
Stress Variations

This paper presents a three-dimensional numerical study to evaluate the variations in stresses in the soil mass surrounding a carbon steel pipe class API 5L X60 submitted to uplift due to ground elevation. Analyses were carried out for soil relative density, pipe stiffness and surficial surcharge loading. Results have shown that stress variations due to uplift are lower for looser backfill soils and flexible pipes. Stress variations in pipe invert are meaningful in the vicinity of the region between stable and unstable soil masses.

Study on the Permeability of Reinforced Soil with Herb Fiber under Different Salt Solution Concentration

2011 ◽  
Vol 308-310 ◽  
pp. 2291-2296
Author(s):  
Geng Sheng Yan ◽  
Hu Yuan Zhang ◽  
Xiao Dong Wang ◽  
Min Li ◽  
Tian Yu Zhao
Keyword(s):  
Diffusion Layer ◽  
Permeability Coefficient ◽  
Particle Surface ◽  
Water Film ◽  
Solution Concentration ◽  
Soil Mass ◽  
Reinforced Soil ◽  
Wet Processing ◽  
Exchange Adsorption ◽  
Flexible Wall

The best is to read these instructions and follow the outline of this text. n this investigation, laboratory permeability tests were conducted on the wet-processing reinforcement specimens to study the feasibility of reinforced soil as a material of construction. Two kinds of reinforced specimens with different reinforcement materials (wheat straw (C) and flax (M)) were mixed with 3% contents of soil mass, and product to the cylindroid for measurement of permeability by a flexible-wall permeameter. The variation relationship between permeability coefficient and Na2SO4 concentrations was analyzed. Test results show that the liquidity reduced with incrassate diffusion layer caused by the increasing Na+ concentrations in the diffusion layer of soil particles, and then a decrease of permeability is found. With the increasing time of permeability, it is found that the permeability coefficient decreased due to the consolidation and decreasing porosity of specimens caused by the change of stress state. At the same time, ion exchange adsorption and water film incrassate occurs in soil particle surface which also benefit to the decrease of permeability coefficient.

scholarly journals Performance of Geosynthetic-Reinforced Soils Under Static and Cyclic Loading

2017 ◽  
Vol 7 (2) ◽  
pp. 1523-1527 ◽  
Author(s):  
M. Touahmia
Keyword(s):  
Cyclic Loading ◽  
Large Scale ◽  
Soil Mass ◽  
Reinforced Soil ◽  
Geosynthetic Reinforcement ◽  
Great Resistance ◽  
Geosynthetic Reinforced Soil ◽  
Confining Pressures ◽  
Pullout Failure ◽  
Static And Cyclic Loading

This paper investigates and discusses the composite behavior of geosynthetic reinforced soil mass. It presents the results of a series of large-scale laboratory tests supported by analytical methods to examine the performance of geogrid reinforcement subjected to static and cyclic pullout loading. The testing equipment and procedures used for this investigation are outlined. The results show that geosynthetic reinforcement can mobilize great resistance to static pulling load under high confining pressures. The reinforcement exhibits gradual deformation under cyclic loading showing no sign of imminent pullout failure for all levels of applied loads. In general, the results demonstrate that geosynthetic can be used in situations where loads are non-static, although care will be required in ensuring that appropriate factors of safety are applied to control the resulting deformation. A simplified analytical model for calculating the pulling capacity of geosynthetic reinforcement is proposed.

scholarly journals Stability Assessment of Coastal Cliffs Incorporating Laser Scanning Technology and a Numerical Analysis

2019 ◽  
Vol 11 (16) ◽  
pp. 1951 ◽  
Author(s):  
Rafal Ossowski ◽  
Marek Przyborski ◽  
Pawel Tysiac
Keyword(s):  
Laser Scanning ◽  
Soil Mass ◽  
Reinforced Soil ◽  
Stability Assessment ◽  
Change Analysis ◽  
Geotechnical Parameters ◽  
Limit Value ◽  
Simplifying Assumptions ◽  
Coastal Cliffs ◽  
The Stability

We investigated the cliff coast in Jastrzebia Gora, Poland. The measurements that were taken between 2014 and 2018 by applying terrestrial, mobile, and airborne laser scanning describe a huge geometric modification involving dislocations in a 2.5 m range. Differential maps and a volumetric change analysis made it possible to identify the most deformed cliff’s location. Part of the monitoring of coastal change involved the measurement of a cliff sector in order to determine the soil mass flow down the slope. A full geometric image of the cliff was complemented by a stability assessment that incorporated numerical methods. The analysis showed that the stability coefficients, assuming a particular soil strata layout and geotechnical parameters, are unsafely close to the limit value. Moreover, the numerical computations, which were performed under simplifying assumptions, were not able to capture a multitude of other random factors that may have an impact on the soil mass stability. Thus, displacements of both reinforced soil and gabions were detected that are intended to prevent the cliff from deforming and to protect the infrastructure in its vicinity. The array of applied measurement methods provides a basis for the development of research aimed at optimization of applied tools, safety improvements, and a rapid reaction to threats.

Evaluation and Recommendations for Flowfill and Mechanically Stabilized Earth Bridge Approaches

2008 ◽  
Vol 2045 (1) ◽  
pp. 51-61
Author(s):  
Naser M. Abu-Hejleh ◽  
Dennis Hanneman ◽  
Trever Wang ◽  
Ilyess Ksouri
Keyword(s):  
Filter Material ◽  
Soil Mass ◽  
Reinforced Soil ◽  
Mechanically Stabilized Earth ◽  
Repair Costs ◽  
Bridge Approach ◽  
Class B ◽  
Class 1 ◽  
Backfill Materials ◽  
Mechanically Stabilized

To alleviate the common bridge bump problem, the Colorado Department of Transportation (CDOT) has employed three new alternatives for bridge abutment backfill since 1992: flowfill, mechanically stabilized earth (MSE) using well-graded granular Class 1 backfill (reinforced soil mass as in MSE walls), and MSE using free-draining Class B filter material. However, the occurrence of bridge bump problems is still reported. A study evaluated CDOT current practice for design and construction of bridge approaches and then developed recommendations to improve this practice (improve performance and reduce costs) on the basis of the results of the following: (a) best practices for bridge approaches collected from CDOT staff and reported in the literature, (b) evaluation of the performance and cost-effectiveness of Colorado's MSE and flowfill bridge approaches, and (c) identification of the causes of significant bridge approach settlement problems observed in some of Colorado's MSE and flowfill bridge approaches. Evaluation procedures and forensic investigations were developed and applied to obtain the information needed for the first two items. Flowfill should remain a viable alternative for certain field and construction scenarios that justify its higher costs. MSE approaches with both Class B and Class 1 backfill materials should be routinely used in future CDOT projects with documentation of their performance and cost (construction and repair costs) for a future evaluation. Comprehensive recommendations are presented to mitigate the observed bridge approach settlement problem; the most important recommendations are for improved support and drainage systems for the sleeper slab where the settlement problem occurs.

scholarly journals Reinforcement of Cohesionless Soil by Multi-oriented Geosynthetic Inclusions

2020 ◽  
Author(s):  
Shwetha Prasanna
Keyword(s):  
Soil Sample ◽  
Laboratory Tests ◽  
Glass Fibers ◽  
Soil Mass ◽  
Soil Samples ◽  
Reinforced Soil ◽  
Cohesionless Soil ◽  
Direct Shear ◽  
Angle Of Internal Friction ◽  
Cbr Test

Henry Vidal first introduced the concept of using strips, grids, and sheets for reinforcing soil masses. Since then, a large variety of materials such as steel bars, tire shreds, polypropylene, polyester, glass fibers, coir, jute fibers etc. have been widely added to the soil mass randomly or in a regular, oriented manner. In this investigation, a new concept of multi-oriented plastic reinforcement (hexa-pods), is discussed. A systematic and comprehensive laboratory tests were conducted on unreinforced and reinforced soil samples. Laboratory tests such as direct shear teat and California bearing ratio (CBR) test were analyzed on soil samples consisting of only soil samples, soil sample with random inclusion of hexapods and soil samples with layered inclusion of hexapods. From the results obtained through direct shear test it could be observed that cohesion value of both the soil sample has increased and the angle of internal friction has been decreased after reinforcing it with inclusions in both randomly and layered conditions. CBR test indicates that for same amount of compactive effort, both random and layered inclusions of hexapods show improvement in strength and stiffness. Random inclusions of hexapods give better resistance to penetration as compared to layered inclusions. The hexa-pods also changed the brittle behavior of unreinforced sand samples to ductile ones.

scholarly journals USE OF ASSEMBLY ASH IN THE COMPOSITION OF SOIL CEMENT

2021 ◽  
Vol 29 (2) ◽  
pp. 51-65
Author(s):  
N. Blaschuk ◽  
◽  
I. Maevska ◽  
M. Goncharuk ◽  
◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Soil Mass ◽  
Ash Content ◽  
Reinforced Soil ◽  
Optimal Composition ◽  
Soil Cement ◽  
Ash Removal ◽  
Practical Recommendations ◽  
Physical And Mechanical Characteristics

Іn this work, we searched for the optimal composition of soil cement containing different percentage of ash removal: from minor additives to the replacement of half the soil mass for ash. The search for the optimal composition was performed on the basis of experimental studies to determine the physical and mechanical characteristics.The use of soil cement with the addition of fly ash is proposed for the reinforcement of the bases by vertical reinforcing elements. In order to develop practical recommendations on the optimal composition of soil cement, a mathematical simulation of the work of reinforced soil cement fields was performed with the variation of the physical and mechanical characteristics of piles, depending on the ash content of the ash. . Plaxis software was used for numerical simulation. With a steady step of reinforcing elements, the properties of the soil-cement mass were studied, depending on the deformability of the piles.

scholarly journals Strengthening of weak foundation soils with crushed stone piles

2020 ◽  
Vol 17 (6) ◽  
pp. 126-131
Author(s):  
Yu. N. Akulova ◽  
◽  
I. I. Sakharov ◽  
V. V. Lushnikov ◽  
◽  
...  
Keyword(s):  
Software Package ◽  
Soil Mass ◽  
Reinforced Soil ◽  
Crushed Stone ◽  
Deformation Characteristics ◽  
The Road ◽  
Vibration Compaction ◽  
Strength And Deformation ◽  
3D Software ◽  
Plaxis 3D

The article presents an innovative technique of deep vibration compaction for soft saturated soils with crushed stone piles. The methods for calculating the strength and deformation characteristics of reinforced soil mass proposed by H. J. Priebe and A. Z. Ter-Martirosyan are presented. An example of the road embankment base in the Plaxis 3D software package is given, taking into account the improvement of the soil mass with crushed stone piles.

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