Evaluating Effects of Cyclic Axial Loading on Soil-Pile Interface Properties Utilizing a Recently Developed Cyclic Interface Shear Test Device

IFCEE 2021 ◽  
2021 ◽  
Author(s):  
Mu’ath I. Abu Qamar ◽  
Muhannad T. Suleiman
Keyword(s):  
Shear Test ◽  
Axial Loading ◽  
Interface Properties ◽  
Test Device ◽  
Interface Shear

Analysis of sand – woven geotextile interface shear behavior using discrete element method (DEM)

2020 ◽  
Vol 57 (3) ◽  
pp. 433-447 ◽  
Author(s):  
Shi-Jin Feng ◽  
Jie-Ni Chen ◽  
Hong-Xin Chen ◽  
Xin Liu ◽  
T. Zhao ◽  
...  
Keyword(s):  
Shear Band ◽  
Discrete Element Method ◽  
Coordination Number ◽  
Direct Shear Test ◽  
Shear Test ◽  
Discrete Element ◽  
Sliding Contact ◽  
Direct Shear ◽  
Interface Shear ◽  
Normal Anisotropy

The interaction between soil and geotextile is essential for the performance of reinforced soil. This study reveals the microscopic mechanism of interface shear between sand and geotextile based on the discrete element method (DEM). The surface characteristics of geotextile are simulated by overlapped particles. The micromechanical parameters of sand, geotextile, and interface are calibrated effectively using laboratory test results. Three types of shear tests on the sand–geotextile interface are simulated; namely, interface direct shear test (IDST), double-sided interface shear test (D_IST), and interface direct shear test with periodic boundary (PBST). For IDST, the results show that the thickness of shear band is 2.4∼3.0 times the average particle diameter (D50); the contact force, percentage of sliding contact, and contact normal anisotropy inside the shear band are larger than those outside the shear band, whereas the coordination number is smaller inside the shear band. The mechanical response of D_IST is similar to that of IDST. However, D_IST has a shear band thickness of 3.0D50, and greater coordination number, percentage of sliding contact, and contact normal anisotropy. The results of PBST indicate that the peak stress and the shear band no longer appear without boundary constraint and the contact distribution is uniform.

Comparison and Review of Concrete-to-Concrete Interface Shear Resistance According to Major Design Codes

2016 ◽  
Vol 249 ◽  
pp. 166-172
Author(s):  
Đorđe Čairović ◽  
František Girgle ◽  
Vojtěch Kostiha ◽  
Jaroslav Kadlec ◽  
Petr Stepanek
Keyword(s):  
Cross Section ◽  
Shear Test ◽  
Shear Resistance ◽  
Design Codes ◽  
Adhesive Failure ◽  
Type Specimens ◽  
Interface Shear ◽  
Model Code ◽  
Model Code 2010 ◽  
Slant Shear

The paper focuses on interface shear behavior, more precisely on shear resistance of the interface between lightweight and regular concrete layers cast at different times without shear reinforcement crossing the interface. Different approaches according to most of major design codes (Eurocode, ACI and Model Code 2010 among other) are briefly reviewed, with emphasis on difference between variables resp. material and cross-section characteristics, on which interface resistance depends. Furthermore, two sets of experiments were carried out: direct shear test on Z-type specimens and slant shear test slightly modified to enforce adhesive failure. Obtained results are compared with theoretical values.

Combined shear and compression analysis using a modified Iosipescu shear test device. Experimental studies on dry wood

Holzforschung ◽  
2005 ◽  
Vol 59 (5) ◽  
pp. 539-545 ◽  
Author(s):  
Federica De Magistris ◽  
Lennart Salmén
Keyword(s):  
Shear Test ◽  
Experimental Studies ◽  
Honeycomb Structure ◽  
Local Deformation ◽  
Homogeneous Material ◽  
Test Device ◽  
Element Analysis ◽  
Compression Load ◽  
New Apparatus ◽  
Iosipescu Shear Test

Abstract The mechanical treatment of wood in a refiner involves a complex combination of shear and compression forces. To obtain more knowledge on this process, the possibility of using an apparatus based on the Iosipescu shear test device to measure the behaviour of wood under a combined shear and compression load was tested. In this new apparatus, different combinations of shear and compression load were achieved by different rotations of the shear test device itself. Numerical simulations of the combined shear and compression test were carried out and compared with experimental data to verify the reliability of the modified device as applied to wood. It was concluded that the new apparatus is suitable for applying different combinations of shear and compression load in testing wood samples. However, finite element analysis showed that with the use of homogeneous material in the model, the level of strain reached would be 10-fold smaller. This fact is probably due to the honeycomb structure of the wood cells, which allows for different local deformation that could not be represented by the continuous material used in the model.

scholarly journals Effects of Relative Roughness and Particle Size on the Interface Behavior of Concrete Suction Caisson Foundation for Offshore Wind Turbines

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5866
Author(s):  
Wang-chun Zhang ◽  
Hao Jing ◽  
Hai-lei Kou
Keyword(s):  
Particle Size ◽  
Shear Stress ◽  
Shear Test ◽  
Friction Angle ◽  
Offshore Wind ◽  
Interface Behavior ◽  
Interface Shear ◽  
Interface Friction ◽  
Offshore Wind Turbines ◽  
Relative Roughness

The interface behavior between a caisson and the surrounding soil plays an important role in the installation of suction caissons as foundations for offshore wind turbines. A series of shear tests were carried out using a modified direct shear apparatus to study the interface shear behavior between sand and concrete. Sand samples with three particle size ranges (0.63–1.25 mm, 1.25–2.5 mm, 2.5–5.0 mm) and concrete plates with different relative roughness were used to explore the influence of the relative roughness parameter (Rn) and mean particle size (D50) on shear behavior. The responses from the pure sand shear test are also discussed for comparison. Test results show that the higher the relative roughness (Rn), the greater the maximum shear stress (τmax) appeared. The interface shear stress was weaker than that of the pure sand test. Furthermore, the interface friction angle (φ) of sand–concrete was closely related to the relative roughness of the concrete surface. Under the same conditions, the interface friction angle (φ) increased with relative roughness due to the effect of sand particles breakage and redistribution. By contrast, the effect of the mean particle size (D50) on the interface friction angle (φ) was less significant. However, for the pure sand shear test, the friction angle (φ′) obtained from the traditional shear test apparently increased with D50, indicating that the friction angle was more affected by D50 in the pure sand test than in the interface shear test.

scholarly journals Assessment of Interface Shear Behaviour of Sub-ballast with Geosynthetics by Large-scale Direct Shear Test

2016 ◽  
Vol 143 ◽  
pp. 1007-1015 ◽  
Author(s):  
M. Mahdi Biabani ◽  
Buddhima Indraratna ◽  
Sanjay Nimbalkar
Keyword(s):  
Large Scale ◽  
Direct Shear Test ◽  
Shear Test ◽  
Shear Behaviour ◽  
Direct Shear ◽  
Interface Shear

scholarly journals Role of normal boundary condition in interface shear test for the determination of skin friction along pile shaft

2017 ◽  
Vol 54 (9) ◽  
pp. 1245-1256 ◽  
Author(s):  
Jianfeng Wang ◽  
Su Liu ◽  
Yi Pik Cheng
Keyword(s):  
Boundary Condition ◽  
Shear Test ◽  
Lateral Boundary Condition ◽  
Penetration Test ◽  
Interface Shear ◽  
Pile Shaft ◽  
Pile Penetration ◽  
Normal Boundary ◽  
Sampling Windows

This paper presents numerical results from a two-dimensional discrete element method (DEM) simulation study on the influence of lateral boundary condition on shaft resistance of a pile driven into a crushable sand. The study was conducted by comparing simulation results from the pile penetration test and the interface shear test employing parallel-bonded agglomerates for modeling of the particle breakage. The interface shear test was performed under three different types of normal boundary conditions; namely, constant normal load (CNL), constant normal stiffness (CNS), and constant volume (CV) boundary conditions. For the pile penetration test, a series of sampling windows were identified on the initial ground configuration to monitor the stress–strain, volume change, and particle breakage behavior of particle groups located within the sampling windows. A detailed investigation was then undertaken by comparing the behavior of particle groups with that from the interface shear test to find out which type of normal boundary condition best describes the lateral boundary condition in the pile penetration test. It has been found that the behavior of a particle group reaches the peak state below the pile tip and the critical state after it reaches the pile shaft. The influence of normal boundary condition on the stress ratio at the critical state is not obvious. The conventional interface shear test (i.e., CNL) can provide valuable information on the determination of skin friction along the pile shaft.

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