When depth of flow past a river bridge exceeds opening under the bridge, the flow under the bridge becomes pressurized. The water is directed downward and under the bridge deck, causing increase in velocity and shear stress on the bed thereby increasing bed scour. This is termed as Pressure Flow Scour. The present study investigates the phenomenon of pressure flow scour resulting from a submerg...

intelligent wells provide the ability for monitoring and control of downhole environment of the wells. downhole monitoring is achieved through sensors while control is realized with downhole valves. recovery from intelligent wells can be improved by proper selection of candidate wells/fields and optimizing the number, location and performance of the installed interval control valves. design cri...

ference in postoperative aortic valve area, maximum velocity across the valve and mortality. Pelletier et al. [8] performed a cohort study comparing 878 CE porcine and 715 Ionescu-Shiley, CE and Mitroflow bovine valves in AVR, MVR or MR from 1976–88. It showed similar late survival rates and clinical improvement. However, the freedom from all valve-related complications was significantly better...

In the coal mining process, the destabilization of loaded coal mass is a prerequisite for coal and rock dynamic disaster, and surface cracks of the coal and rock mass are important indicators, reflecting the current state of the coal body. The detection of surface cracks in the coal body plays an important role in coal mine safety monitoring. In this paper, a method for detecting the surface cr...

This paper presents a method for predicting initial trajectories of propagation of two separate fatigue cracks, which are developed under two perpendicular cyclic loads with phase difference between them. Calculation of trajectories of these two initial cracks is the first step in prediction of trajectories and rate of propagation of long cracks. This problem is important for analysis of durabi...

Development of macro and micro cracks on plastered walls and floors have been studied at different sites under site investigation whereby building inspections, construction history, engineering properties of soil and building surroundings assessment were conducted. We did revision of structural calculations and laboratory experiment to find out the source of cracks. Micro and macro cracks have ...

frps (fiber reinforced polymer) possess many favorable characteristics suitable and applicable for construction industry when compared with steel reinforcement. there are new ideas to use frps as longitudinal or transverse reinforcement for new concrete elements particularly for bridge decks or beams. although high tensile strength of frp is main characteristic for applications at both areas, i...

Abstract The box girder of the Miaoziping Bridge, a three-span prestressed concrete continuous rigid-frame bridge, suffered serious crack in its section’s web near 1/6 to 1/2 length side span and middle-span 1/4 3/4, as result 2008 Wenchuan earthquake, which also caused large lateral residual displacements at both ends span. In this study, eight strong-motion records bridge site two other (El C...

A defect sensing method based on electrical impedance spectroscopy is proposed to image cracks and reinforcing bars in concrete structures. The method utilizes the frequency-dependent behavior of thin insulating cracks: low-frequency electrical currents are blocked by insulating cracks, whereas high-frequency currents can pass through thin cracks to probe the conducting bars. From various frequ...

To improve the selectivity of closed cracks for objects other than cracks in ultrasonic imaging, we propose an extension of a novel imaging method, namely, subharmonic phased array for crack evaluation (SPACE) as well as another approach using the subtraction of responses at different external loads. By applying external static or dynamic loads to closed cracks, the contact state in the cracks ...