Geosynthetic/Soil Interface Friction Angles Using a Rotation Shear Device

1995 ◽  
Vol 18 (2) ◽  
pp. 271 ◽  
Author(s):  
HJ Pincus ◽  
MD Evans ◽  
TJ Fennick
Author(s):  
Lawrence Willem De Leeuw ◽  
Matthew S Dietz ◽  
Henry Milewski ◽  
George Mylonakis ◽  
Andrea Diambra

Pipelines in the offshore sector make common use of polypropylene (and other polymer) coating systems to protect the infrastructure and provide thermal insulation. High Pressure High Temperature (HPHT) pipelines are subject to large axial loads due to restraint by seafloor soils of thermal strains in the pipe wall. Friction between pipe coating material and seafloor soil plays a defining role in the build-up of axial stress and the formation of lateral buckling. Accurate quantification of pipe-soil interface friction is key to robust pipeline stability design and possibilities to enhance or manipulate the friction coefficient may be attractive to designers. An extensive campaign of soil and interface tests using a range of granular materials and polypropylene surface specimens engineered to achieve varying surface textures was carried out. The results show that interface friction primarily depends on stress level and the magnitude of the surface texture in relation to the particle size. Herein, a new relative textural parameter, Ta, is developed that, unlike alternative relative roughness parameters, can be obtained using conventional profilometry measurement techniques. An expression for estimating the friction factor in relation to texture and stress level is proposed which can serve as a useful predictor of pipe-soil interface friction.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Meng Xiong ◽  
Pengfei He ◽  
Yanhu Mu ◽  
Xinlei Na

The shear behaviors of concrete-frozen soil interface are important for analyzing the performance of engineering structures buried in the frozen ground. In this paper, a series of direct shear tests were carried out to determine the concrete-soil interface behaviors at different test temperatures (19°C, −1°C, −3°C, and −5°C) and initial water contents (9.2%, 13.1%, 17.1%, and 20.8%) of soils. The interface shear behaviors, including the shear stress versus horizontal displacement, interface cohesion, and interface friction coefficient, were analyzed based on the test results. Then, a simple, nonlinear model was proposed and verified for the interface shear behaviors. The results show that the effect of initial water content and test temperature on the interface shear behavior is significant, and the peak stress increases with the increasing initial water content and decreasing test temperature. The interface cohesion is sensitive to the test temperature and initial water content, while the interface friction coefficient is insensitive to both the factors. The parameters of the simple nonlinear model can be gained by back-analyzing the test results. The predictions made by the proposed model are found to be in good agreement with the experimental results.


2008 ◽  
Vol 15 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Jerome B. Johnson ◽  
James D. Cargile ◽  
Donald M. Smith

A physical model of low-velocity probe penetration is developed to characterize soil by type, strength, maximum compaction, and initial density using Newton's second law to describe the processes controlling probe momentum loss. The probe loses momentum by causing soil failure (strength), accelerating and compacting soil around the probe (inertia), and through frictional sliding at the probe/soil interface (friction). Probe geometry, mass, and impact velocity influences are incorporated into the model. Model predictions of probe deceleration history and depth of penetration agree well with experiments, without the need for free variables or complex numerical simulations.


Author(s):  
Ping Lu ◽  
Dajun Yuan ◽  
Jian Chen ◽  
Dalong Jin ◽  
Jun Wu ◽  
...  

2020 ◽  
Vol 857 ◽  
pp. 203-211
Author(s):  
Majid Hamed ◽  
Waleed S. Sidik ◽  
Hanifi Canakci ◽  
Fatih Celik ◽  
Romel N. Georgees

This study was undertaken to investigate some specific problems that limit a safe design and construction of structures on problematic soils. An experimental study was carried out to examine the influence of loading rate and moisture content on shear strength of organic soil. Influece of moisture content on interface friction between organic soil and structural materials was also attempted. A commonly used soil in Iraq was prepared at varying moisture contents of 39%, 57% and 75%. The experimental results showed that the increase in water content will decrease the shear stress and the internal friction angle. An increase of the shearing rate was found to decrease the shear stress and internal friction angle for all percetanges of water contents. Further, direct shear tests were carried out to detect the interface shear stress behavior between organic soil and structural materials. The results revealed that the increase in water content was shown to have significant negetavie effects on the interface internal friction and angle shear strength.


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