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原文传递 SRICOS: PREDICTION OF SCOUR RATE AT BRIDGE PIERS

题名：	SRICOS: PREDICTION OF SCOUR RATE AT BRIDGE PIERS
作者：	Jean-Louis Briaud, Francis Ting, H. C. Chen, Rao Gudavilli, Kiseok Kwak, Bertrand Philogene, Seung-Woon Han, Suresh Perugu, Gengsheng Wei, Prahoro Nurtjahyo, Yiwen Cao, and Ya Li
关键词：	Scour, Bridges, Bridge Piers, Cohesive Soils, Foundations, Erosion Rate
摘要：	A new method called SRICOS is proposed to predict the scour depth z versus time t around a cylindrical bridge pier of diameter D founded in clay. The steps involved are: 1. taking samples at the bridge pier site; 2. Testing diem in an erosion function apparatus (EFA) to obtain the scour rate z versus the hydraulic shear stress applied t; 3. predicting the maximum shear stress that will be induced around the pier by the water flowing at v0 before the scour hole starts to develop; 4. using the measured z versus t curve to obtain the initial scour rate 4 corresponding to Tmax, 5. predicting the maximum depth of scour for the pier, 6. using 4 and z^ to develop the hyperbolic function describing the scour depth z versus time t curve; and 7. reading the z versus t curve at a time corresponding to the duration of the flood to find the scour depth that will develop around that pier. A new apparatus is developed to measure the z versus t curve of step 2, a series of advanced numerical simulations are performed to develop an equation for the value of step 3, and a series of flume tests are performed to develop an equation for the z^ value of step 5. The method is evaluated by comparing predictions and measurements in 42 flume experiments. The method is extended to include a random velocity-time history and a multilayer soil stratigraphy; it is called the extended SRICOS or E-SRICOS. The algorithms to accumulate the effects of different velocities and to sequence through a series of soil layers are described. The procedure followed by the computer program to step into time is outlined. A simplified version of E-SRICOS called S-SRICOS is also presented; calculations for the SSRICOS method can easily be done by hand. Eight bridges in Texas are used as case histories to compare predictions by the two new methods(E-SRICOS and S-SRICOS) with measurements at the bridge sites.
报告类型：	科技报告