scholarly journals Shear strength properties of Hong Kong soils for slope stability

2020 ◽  
Vol 27 (1) ◽  
pp. 48-54
Author(s):  
Hong Yau Wong
Keyword(s):  
Shear Strength ◽  
Hong Kong ◽  
Slope Stability ◽  
Triaxial Compression ◽  
Quantitative Relationship ◽  
Site Investigation ◽  
Standard Penetration Test ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Soil Shear Strength

With the recent advancement in technology, the method, accuracy and speed of slope stability analysis have been vastly improved. Nevertheless, the reliability and appropriateness of such analysis can be very much in doubt if the soil behaviour, in particular the shear strength behaviour, is not fully understood. The objective of this paper is therefore to evaluate the shear strength behaviour of various soil types in Hong Kong. This comprises the collection, processing and analysis of the laboratory and field works carried out in the past few decades, in particular the triaxial compression testing in the laboratory and standard penetration test (SPT) in the field. For correlating SPT with soil shear strength, a fairly large number of carefully controlled site investigation works with SPT are carried out both above and below any Mazier sampling. Laboratory triaxial tests are then carried out in these Mazier samples. Finally, it is hoped that a basically quantitative relationship between soil shear strength and SPT can be obtained as this would enable a soil shear strength profile to be established once the corresponding SPT profile has been determined on site by carrying out SPT in adequate number of drill holes.

Anisotropic shear strength of a residual soil of sandstone

2008 ◽  
Vol 45 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Adriano Virgilio Damiani Bica ◽  
Luiz Antônio Bressani ◽  
Diego Vendramin ◽  
Flávia Burmeister Martins ◽  
Pedro Miguel Vaz Ferreira ◽  
...  
Keyword(s):  
Shear Strength ◽  
Effective Stress ◽  
Yield Surface ◽  
Triaxial Compression ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Residual Soil ◽  
Compression Tests ◽  
Soil Stiffness ◽  
Particle Bonding

This paper discusses results of laboratory tests carried out with a residual soil originated from the weathering of eolian sandstone from southern Brazil. Parent rock features, like microfabric and particle bonding, are remarkably well preserved within this residual soil. Stiffness and shear strength properties were evaluated with consolidated drained (CID) and consolidated undrained (CIU) triaxial compression tests. Undisturbed specimens were tested with two different orientations between the specimen axis and bedding surfaces (i.e., parallel (δ = 0°) or perpendicular (δ = 90°)) to investigate the effect of anisotropy. When CID triaxial tests were performed with δ = 0°, the yield surface associated with the structure was much larger than when tests were performed with δ = 90°. Coincidently, CIU tests with δ = 0° showed peak shear strengths much greater than for δ = 90° at comparable test conditions. Once the peak shear strength was surpassed, CIU tests followed collapse-type effective stress paths not shown by corresponding tests with remolded specimens. A near coincidence was observed between the yield surface determined with CID tests and the envelope of collapse-type effective stress paths for δ = 0° and δ = 90°.

Study on Shear Strength of Expansive Soil Considered Softening by Triaxial Tests

2014 ◽  
Vol 1065-1069 ◽  
pp. 76-80
Author(s):  
Jun Hua Wu
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Shear Strain ◽  
Expansive Soil ◽  
Strength Criterion ◽  
Triaxial Tests ◽  
Plastic Shear ◽  
Soil Slope ◽  
Plastic Shear Strain ◽  
Soil Shear Strength

Swell-shrinking, crack development and over-consolidation are the characteristics of expansive soil, and it is an over-consolidation soil undergone dry-wet cycles. So there may be some faults to analyze expansive soil slope stability adopting the traditional strength criterion and calculation methods. In this paper, triaxial tests were carried out to obtain the relations between the parameters of shear strength and generalized plastic shear strain. The soil shear strength increases and then decreases along with the increasing of shear deformation due to soil over-consolidation. Moreover, the residual strength is achieved finally. The functions are applied in simulating the relations between the parameters and generalized plastic shear strain in order to analyze expansive soil slope stability.

Deep sampling and testing in soft stratified clay

2003 ◽  
Vol 40 (3) ◽  
pp. 575-586 ◽  
Author(s):  
Simon James Cummings ◽  
Vinayagamoorthy Sivakumar ◽  
Isaac Gregg Doran ◽  
Jim Graham
Keyword(s):  
Triaxial Compression ◽  
Relevant Literature ◽  
Thick Layer ◽  
Site Investigation ◽  
Anisotropic Elasticity ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Lower Zone ◽  
A Site ◽  
Triaxial Compression Tests

A 37-m thick layer of stratified clay encountered during a site investigation at Swann's Bridge, near the sea-coast at Limavady, Northern Ireland, is one of the deepest and thickest layers of this type of material recorded in Ireland. A study of the relevant literature and stratigraphic evidence obtained from the site investigation showed that despite being close to the current shoreline, the clay was deposited in a fresh-water glacial lake formed approximately 13 000 BP. The 37-m layer of clay can be divided into two separate zones. The lower zone was deposited as a series of laminated layers of sand, silt, and clay, whereas the upper zone was deposited as a largely homogeneous mixture. A comprehensive series of tests was carried out on carefully selected samples from the full thickness of the deposit. The results obtained from these tests were complex and confusing, particularly the results of tests done on samples from the lower zone. The results of one-dimensional compression tests, unconsolidated undrained triaxial tests, and consolidated undrained triaxial compression tests showed that despite careful sampling, all of the specimens from the lower zone exhibited behaviour similar to that of reconstituted clays. It was immediately clear that the results needed explanation. This paper studies possible causes of the results from tests carried out on the lower Limavady clay. It suggests a possible mechanism based on anisotropic elasticity, yielding, and destructuring that provides an understanding of the observed behaviour.Key words: clay, laminations, disturbance, yielding, destructuring, reconstituted.

Mechanical Properties of Bentonite-Sand Mixtures Under Triaxial Stress Condition

1994 ◽  
Vol 353 ◽  
Author(s):  
M. Umedera ◽  
A. Fujiwara ◽  
N. Yasufuku ◽  
M. Hyodo ◽  
H. Murata
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Water Content ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Strength Properties ◽  
Compression Tests ◽  
Optimum Water Content ◽  
Triaxial Compression Tests ◽  
Optimum Water

AbstractA series of triaxial compression tests is being conducted under the drained condition on bentonite and sand mixtures, known as buffer, in saturated and optimum water content states to clarify the mechanical properties of the buffer.It was found that the mechanical properties of bentonite and sand mixtures are strongly influenced by water and bentonite contents: shear strength in a saturated state is less than that in an optimum water content state; shear strength decreases rapidly with increasing bentonite content. Strength properties are much dependent on confining pressure.

Sample Disturbance in Soft Alluvial Clyde Estuary Clay

1974 ◽  
Vol 11 (4) ◽  
pp. 651-660 ◽  
Author(s):  
A McGown ◽  
L. Barden ◽  
S. H. Lee ◽  
P. Wilby
Keyword(s):  
Shear Strength ◽  
Electron Microscope ◽  
Site Investigation ◽  
Triaxial Tests ◽  
Foundation Design ◽  
Site Investigations ◽  
Testing Techniques ◽  
Sample Disturbance ◽  
Area Standard ◽  
Scanning Electron

The alluvium of the Clyde Estuary provides the foundation material for a number of medium rise developments in the Glasgow area. Standard site investigation and testing techniques often result in an expensive foundation design involving piling. A more sophisticated investigation conducted at Laurieston, has afforded a chance to compare the disturbance due to different qualities of sampling. The degree of disturbance to macro- and microstructure has been assessed using standard photographic techniques and a scanning electron microscope. The effect of disturbance on shear strength has been measured using hand vane and triaxial tests; and on consolidation and compression parameters using Rowe cells of different sizes. On the basis of the standard and the improved site investigations two foundation designs have been prepared and their cost compared.

scholarly journals Comparison of Mechanical Properties of Fiber-Reinforced Sand under Triaxial Compression and Direct Shear

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Reza Noorzad ◽  
Seyed Taher Ghoreyshi Zarinkolaei
Keyword(s):  
Shear Strength ◽  
Axial Strain ◽  
Triaxial Compression ◽  
Polypropylene Fiber ◽  
Triaxial Tests ◽  
Direct Shear ◽  
Test Results ◽  
Peak Reduction ◽  
Shear Tests ◽  
Direct Shear Tests

AbstractThis research investigates the behavior of sand reinforced with polypropylene fiber. To do this, 40 direct shear tests and 40 triaxial tests were performed on the coastal beaches of Babolsar, a city in the North of Iran. The effect of parameters such as fiber content, length of fiber and normal or confining pressure on the behavior of Babolsar sand have been studied. In this study, four various fiber contents (0, 0.25, 0.5 and 1 percent), three different lengths of fiber (6, 12 and 18 mm) and four normal or confining pressures (50, 100, 200 and 400 kPa) have been employed. The test results show that fiber inclusion has a significant effect on the behavior of sand. In both direct shear and triaxial tests, the addition of fibers improved shear strength parameters (C, '), increased peak shear strength and axial strain at failure, and also limited the amount of post-peak reduction in shear resistance. The comparison of the test results revealed that due to better fiber orientation toward the direction of principal tensile strain in triaxial test as compared to direct shear tests, the fiber efficiency and its effect on soil behavior is much more significant in triaxial specimens.

scholarly journals Pengujian Geser Limestone Untuk Menghitung Angka Keamanan Terhadap Kelongsoran Di Utama Mandala Pura Uluwatu

2019 ◽  
Vol 24 (1) ◽  
pp. 13
Author(s):  
I Nyoman Ramia ◽  
I Wayan Arya ◽  
I Wayan Wiraga ◽  
I G A G I G A G Suryanegara
Keyword(s):  
Shear Strength ◽  
Slope Stability ◽  
Direct Shear Test ◽  
Shear Test ◽  
Dead Load ◽  
Soil Shear Strength ◽  
Engineering Department ◽  
Sliding Test ◽  
The Stability ◽  
The Temple

The shear strength value is one of the important points in calculation of slope stability. One way to obtain the shear strength value is to do a direct shear test in laboratory. Like the cliff reinforcement study at Utama Mandala Uluwatu temple which is currently experiencing crack, it is necessary to test the shear strength of the limestone material at the cliff of the temple . There is no limestone testing equipment in the laboratory of the Civil Engineering Department, so that innovation is needed on the existing sliding test equipment. In this study innovation was carried out on how to test the soil shear strength so that it could be used to test the limestone shear strength. The test is done by moving two limestone surface that have been formed based on the mold tool which shape is circle. The shear strength slope at Uluwatu temple, which is currently experiencing crack in dry condition is . The shear strength value is used for calculating slope stability at Uluwatu Temple which is currently experiencing crack wich . The calculation used is curved slope stability by only calculate the life load and dead load. From the calculation of the stability of the slope, the safety factor is 1.15.

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.

Influence of Fouling and Water Content of Ballast on Railway Substructure Bearing Capacity

2017 ◽  
Author(s):  
A. K. Rohrman ◽  
H. F. Kashani ◽  
C. L. Ho
Keyword(s):  
Slope Stability ◽  
Bearing Capacity ◽  
Water Content ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Repeated Loading ◽  
Layered System ◽  
Modes Of Failure ◽  
Track System ◽  
Track Substructure

The performance of ballasted railway systems is commonly compromised by the infiltration of fine material into the voids of the ballast. This sand and finer grained materials in the ballast is known as fouling. Increased fouling can cause decreases in hydraulic conductivity and shear strength of the ballast, as well as reduce stiffness and resilient modulus of the overall track system. These problems can cause gradual deterioration of the track, which could eventually require maintenance. One of the largest source of fouling comes from ballast breakdown resulting from abrasion caused under repeated loading. This study aims to investigate the effects of fouling from ballast breakdown on the bearing capacity of the substructure that supports the rail superstructure. Previous investigations at the University of Massachusetts Amherst utilized large scale 10-inch (25.4 cm) diameter triaxial tests on granitic ballast with fouling from ballast breakdown. The tests were run with fouling contents of 0% (clean ballast), 15%, and 30% and at water contents varying from dry ballast to field capacity. Confining pressures of 5 psi (34.5 kPa), 10 psi (68.9 kPa) and 15 psi (103.4 kPa) were used in this series of tests. Using the results from these tests, the Mohr-Coulomb strength properties can be determined for each case. This study will make use of the strength properties obtained from the results of these tests and apply them using two commonly used bearing capacity analyses. The first model is the Meyerhof and Hanna Method which considers the track as a continuous footing over a layered system. This model considers two modes of failure; punching of an individual sleeper, and track system bearing. The second model applied is the slope stability method, which uses a two-dimensional limit equilibrium approach and the method of slices to determine a factor of safety against slope stability. This analysis is commonly performed using various software programs. In this study, SLOPE/W from the GeoStudio software package is utilized for analysis. The factors of safety resulting from the bearing capacity analysis using these two methods will be compared for each of the test configurations performed, which will help to confirm the results of the analyses. Since the Mohr-Coulomb strength properties change with the degree of fouling and the water content of the ballast, it is expected that this will have some effect on the bearing capacity of the track substructure. The results of these analyses showing the effects of water content and fouling of ballast on overall track substructure bearing capacity are presented in this paper.

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