Comprehensive Diagnostic Analysis And Engineering Renovation On The Stability Of Wharf’s Rubble Bed Under The Scouring Effect Of Towboat Stern Flow

In the paper, we use prototype measurement，mathematical mode,physical modelfor a comprehensive diagnostic analysis on the stability of wharf’s rubble bed underthe scouring effect of towboat stern flow,and puting forward a suitable engineeringsolutions. The main work of this paper includes the following several aspects:1.The part discusses a engineering detection method after rubble bed is scoured.Combined with practical engineering, the diving explored examination andmulti-beam underwater topographic survey and other modern testing technology isused to locate the position,determine the extent of rubble bed damaged. The1176kWZ tug is chosen as the test object to measure velocity of flow, reproduce the scene thatrubble bed under the scouring effect of towboat stern flow. Finally, according to thecharacteristics of rubble bed damaged, we adopted respectively the standardcalculation and mathematical model calculation to evaluate comprehensively thesafety of wharf,and put forward a new concept of limit depth into wharf, it is pointedout when the scour depth exceeds the limit depth, the whatf will failure.2.This is a study on the mathematical model of wharf’s rubble bed. Firstproposed two-dimensional simplified model for stone starting velocity of wharf’srubble bed. Through the study on the level of single stone starting velocity andscouring mechanism, to verify the rationality and the reliability of the simplifiedmodel, and further the study discovered that the conditions of cloak between closerstones make the incipient velocity quite different, and present a new Izzy Bashcorrection formula. On this basis, ADINA software is used to establish fluid-solidcoupling numerical model to study the stability than various flow scouring the weightof different stone. And comprehensive analysis the influence on the rubble bed withthe incoming flow and inverse flow, to obtain the stone starting velocity fielddistribution and starting conditions.3.Using the physical model research on rubble bed stability by water flow.Selection of length14m, width8m, height1.2m open rectangular pool as a testpool,and selected particles uniformly stone as a test bed rock. Use of submersiblepump simulation tug propeller jet flow, control the flow rate of the study area byadjusting the different power submersible pump position.The advanced doppler-pointcurrent meter can measure the flow rate of the base bed riprap leading and trailingedge, to get flow rate indicators that can cause damage to the rubble bed stability. Finally, practical engineering verified the reliability of this model research results4.This part have made a close study of reinforcement methods of rubble beddamaged. Three kinds of traditional reinforcement methods is introduced to solve thatrubble bed is scoured by towboat stern flow. Combined with the engineeringcharacteristics,the thesis proposed the reinforcement construction scheme that filledthe holes under caisson foreland with underwater unscattered concrete and used themold bag concrete to protection of face,slope protection,bottom stabilizing.Thescheme aimed at restoring and enhancing the original design top elevation,stressedperformance of rubble bed, the foundation bed coefficient and anti-erosion ability inthe strong flow environment...