Effect of fracture deformation on fluid pressure distribution - an indicator of slope instability

1978 ◽  
Vol 15 (5) ◽  
pp. A113
Keyword(s):  
Pressure Distribution ◽  
Fluid Pressure ◽  
Slope Instability ◽  
Fracture Deformation

Effect of fracture deformation on fluid pressure distribution—an indicator of slope instability

1977 ◽  
Vol 14 (3) ◽  
pp. 302-309 ◽  
Author(s):  
John E. Gale ◽  
Paul A. Witherspoon
Keyword(s):  
Fractured Rock ◽  
Fluid Pressure ◽  
Field Tests ◽  
Tangential Component ◽  
Slope Instability ◽  
Normal Displacement ◽  
Fracture Plane ◽  
Effective Normal Stress ◽  
Pressure Distributions ◽  
Fracture Deformation

Results from laboratory and field tests on fractured rock systems have shown that changes in fluid pressure within a fracture can cause changes in the effective normal stress that result in significant normal displacements. These normal displacements change the fluid pressure distributions and hence the shear strength of the fracture system. The nature of the normal displacement (opening or closing of the fracture) can be detected by comparing the ratios of pressures measured at two points within the fracture plane. Other workers have shown in laboratory shear tests on rough fractures that movement along discontinuities, prior to failure, has both a normal and tangential component. Careful measurement of changes in fluid pressures in fractured rock slopes should be able to detect the effects of such normal displacements and thus give an indication of an approaching instability.

Dynamics of Interstitial Fluid Pressure in Extracellular Matrix Hydrogels in Microfluidic Devices

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Joe Tien ◽  
Le Li ◽  
Ozgur Ozsun ◽  
Kamil L. Ekinci
Keyword(s):  
Extracellular Matrix ◽  
Pressure Distribution ◽  
Interstitial Fluid ◽  
Scaling Laws ◽  
Fluid Pressure ◽  
Interstitial Fluid Pressure ◽  
External Loading ◽  
Interstitial Pressure ◽  
Time Resolved ◽  
Long Time

In order to understand how interstitial fluid pressure and flow affect cell behavior, many studies use microfluidic approaches to apply externally controlled pressures to the boundary of a cell-containing gel. It is generally assumed that the resulting interstitial pressure distribution quickly reaches a steady-state, but this assumption has not been rigorously tested. Here, we demonstrate experimentally and computationally that the interstitial fluid pressure within an extracellular matrix gel in a microfluidic device can, in some cases, react with a long time delay to external loading. Remarkably, the source of this delay is the slight (∼100 nm in the cases examined here) distension of the walls of the device under pressure. Finite-element models show that the dynamics of interstitial pressure can be described as an instantaneous jump, followed by axial and transverse diffusion, until the steady pressure distribution is reached. The dynamics follow scaling laws that enable estimation of a gel's poroelastic constants from time-resolved measurements of interstitial fluid pressure.

Dynamic Interactions Between the Vadose and Phreatic Zones During Breaking Solitary Wave Runup and Drawdown Over a Fine Sand Beach

2009 ◽  
Author(s):  
Heng Xiao ◽  
Yin L. Young ◽  
Jean H. Pre´vost
Keyword(s):  
Porous Media ◽  
Solitary Wave ◽  
Fluid Pressure ◽  
Fine Sand ◽  
Laboratory Scale ◽  
Slope Instability ◽  
Multiphase Model ◽  
Wave Runup ◽  
Sand Beach ◽  
Dynamic Interactions

The objective of this work is to investigate the dynamic interactions between the vadose and the phreatic zones during breaking solitary wave runup and drawdown over a fine sand beach. Extreme wave runup and drawdown in the nearshore region can lead to soil failure in the form of severe erosion, liquefaction, or slope instability. However, the physics of the nearshore region is difficult to simulate numerically due to the greatly varying time scales between the four governing processes: loading and unloading caused by wave runup and drawdown, propagation of the saturation front, pore pressure diffusion, and soil consolidation. Such processes are also difficult to simulate experimentally via model-scale wave tank studies due to the inability to satisfy all the similarity requirements for both the wave and the porous media in a 1g environment. Hence, the goal of this work is to perform a 1D study using a multiphase model to describe the transient responses of the species saturation, pore fluid pressure, effective stresses, and skeleton deformation. Results are shown for three simulations: (1) full-scale simulation, (2) 1:20 laboratory-scale simulation without scaling of the porous media, and (3) 1:20 laboratory-scale with consistent scaling of the soil permeability. The results suggest that the scaling of porous media between the pore fluids and soil skeleton has a significant influence on the transient response of both the vadose and the phreatic zones.

Fluid pressure distribution due to outer hair cell excitation in a 3‐D dual chamber model of cochlea

1999 ◽  
Vol 106 (4) ◽  
pp. 2204-2204 ◽  
Author(s):  
Anand A Parthasarathi ◽  
Karl Grosh ◽  
Tianying Ren ◽  
Alfred L Nuttall
Keyword(s):  
Hair Cell ◽  
Pressure Distribution ◽  
Outer Hair Cell ◽  
Fluid Pressure ◽  
Dual Chamber ◽  
Chamber Model

Fluid pressure distribution in an aerated hopper

AIChE Journal ◽  
1980 ◽  
Vol 26 (2) ◽  
pp. 297-299
Author(s):  
H. Kubilay Altiner
Keyword(s):  
Pressure Distribution ◽  
Fluid Pressure

Elastomer Seal With Frictional Contact: Analytical Solution

2013 ◽  
Author(s):  
Moosa S. M. Al-Kharusi ◽  
Sayyad Zahid Qamar ◽  
Tasneem Pervez ◽  
Maaz Akhtar
Keyword(s):  
Analytical Solution ◽  
Pressure Distribution ◽  
Closed Form ◽  
Numerical Models ◽  
Fluid Pressure ◽  
Closed Form Solution ◽  
Field Conditions ◽  
Design Parameters ◽  
Sealing Pressure ◽  
Elastomer Seal

Main motivation for this work is the need for performance evaluation of swelling (and inert) elastomer seals used in petroleum applications. Closed-form (analytical) solutions are derived for sealing pressure distribution along the elastomer seal as a function of material properties of the elastomer, seal geometry and dimensions, seal compression, and differential fluid pressure acting on the seal ends. Seal performance is also modeled and simulated numerically. Good agreement between analytical and numerical results gives confidence that the analytical solution can be used for reliable prediction of sealing behavior of the elastomer. Detailed investigation is then carried out to find out the effect of variation in seal design parameters on seal performance. For both analytical and numerical models, properties of the seal material at various stages of swelling are needed. Therefore, a series of experiments were also designed and conducted to study the effect of swelling on mechanical properties (E, G, K, and ν) of the sealing material. One major finding is that sealing pressure distribution along the seal is not constant but varies nonlinearly depending on seal parameters and loading conditions, with maximum sealing pressure occurring at the center of the seal length. Longer seals are not necessarily better; after a certain seal length, sealing pressure reaches a steady value for a given set of field conditions. As expected, higher seal compression gives higher sealing pressure. Seal compression can be increased either by tubular expansion or by selecting an elastomer that swells more, or a combination of the two. Experimental evaluation of swelling-elastomer seal performance can be very costly, and is not even possible in many cases. Numerical simulations, if validated, can be more convenient, but computational effort and cost can be high as simulations have to be run for each set of conditions. Analytical approach presented here not only gives an elegant closed-form solution, but can give reasonably accurate and much faster prediction of elastomer performance under various actual oil and gas field conditions.

Characteristics of Deep Abnormal High Pressure and its Controlling on Hydrocarbon Accumulation in Zhanhua Sag

2014 ◽  
Vol 628 ◽  
pp. 376-382
Author(s):  
Qiu Hua Shi ◽  
Bin Xia ◽  
Zhi Feng Wan ◽  
Ya Juan Yuan
Keyword(s):  
High Pressure ◽  
Pressure Distribution ◽  
Sedimentary Basin ◽  
Fluid Pressure ◽  
Hydrocarbon Generation ◽  
Pore Fluid Pressure ◽  
Pressure System ◽  
Abnormal Pressure ◽  
Ultrasonic Time ◽  
Key Factor

Study on abnormal pressure of sedimentary basin is of great significance. According to the ultrasonic time difference method and measured practical data, some sectional and planar pressure distribution of Zhanhua Sag are obtained while most belong to overpressure, and the pressure distribution and the formation mechanism of high pressure are also analyzed. It is showed that the pore fluid pressure of Es3 and the upper part of Es4 members are higher in Bonan subsag and Gubei subsag and the distribution of abnormal high pressure reached a maximum at the early Es3. The disequilibrium compaction, hydrocarbon generation and some clay mineral dehydration are suggested to contribute to the formation of normal high pressure, including the rapid deposition as one of the most key factor. The lower part of Es3 and Es4 themselves within the deep high pressure system, as good lithologic reservoirs, can transport oil to the upper formation by episodic release to form allochthonous atmospheric hydrocarbon reservoirs.

An Investigation Hydrodynamic Fluid Pressure at Wedge-Shaped Gap between Grinding Wheel and Workpiece

2010 ◽  
Vol 44-47 ◽  
pp. 970-974
Author(s):  
Chang He Li ◽  
Jing Yao Li ◽  
Ya Li Hou
Keyword(s):  
Pressure Distribution ◽  
Fluid Pressure ◽  
Hydrodynamic Pressure ◽  
Contact Length ◽  
Coolant Fluid ◽  
Grinding Wheel ◽  
Maximum Pressure ◽  
Work Surface ◽  
Good Surface ◽  
Peripheral Surface

In the grinding process, conventional method of flood delivering coolant fluid by a nozzle in order to achieve good surface integrity. However, hydrodynamic fluid pressure can be generated ahead of the contact zone due to the wedge effect between wheel peripheral surface and work surface. In the paper, a theoretical hydrodynamic pressure modeling is presented for flow of coolant fluid through the grinding zone in flood delivery grinding. Moreover, coolant induced force can be calculated by integrate the hydrodynamic pressure distribution over the whole contact length. The theoretical results show that the hydrodynamic pressure was proportion to grinding wheel velocity, and inverse proportion to the minimum gap between wheel and work surface and the maximum pressure value was generated just in the minimum gap region in which higher fluid pressure gradient occuring. It can also be concluded the pressure distribution was uniform in the direction of width of wheel except at the edge of wheel because of the side-leakage.

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