Sand beach erosion amount predicting method

Abstract

A sand beach erosion amount predicting method comprises the following steps that firstly, the breaking wave height Hb is calculated, Hb=0.39g<0.2>(TH0<2>)<0.4>, g is the gravitational acceleration, H0 is the deepwater wave height, T is the wave period, T0 is the wave duration time, and h is the sand beach water increasing depth; secondly, the wave speed u0, shown in the specification, at the sand beach position is calculated; thirdly, the wave number Ni corresponding to different wave heights is calculated; fourthly, the erosion shear stress caused to the beach face from the waves is calculated, Tauw=0.5FwRhowu0<2>, in the formula, Fw is the friction coefficient between water flow and a soil body, and rhow is the seawater density; fifthly, the sandy soil anti-erosion critical shear stress is calculated, tauc=2/3 ds (rhos-rhow) g tanphi, ds is the sandy soil median size, rhos is the sand grain density, and phi is the internal friction angle of sandy soil; and sixthly, the sand beach erosion amount shown in the specification is calculated, in the formula, Es is the wave erosion amount, Ni is the wave number corresponding to the ith wave height, Ks and a are conversion coefficients for converting the erosion force into the erosion amount, and a is 1.0. The method has the beneficial effects that steps are simple, and the result is reliable, and providing the theoretical guidance for sand beach disaster reduction and protection is the purpose.

Description

technical field [0001] The invention relates to a prediction method for beach erosion under the action of strong waves in typhoon weather. Background technique [0002] The southeast coast of my country is affected by several strong typhoons every year. The strong waves caused by the typhoon have a greater impact on the beach sand. erosion. Take the "Moratti" typhoon in 2016 as an example. The waves caused by the typhoon caused serious erosion of Xiamen Beach. According to the survey, the erosion of Wuguan Beach in Haicang reached a height of 10-15cm. Reach 23 ~ 54cm height. For beach erosion, in addition to on-site investigation, it is a better method to use theoretical models to predict. Most of the current prediction methods are based on the transport model of sediment, the source of sediment and the characteristics of waves and currents. Most of these methods are relatively complicated. , some parameters are difficult to determine, and it is not easy for engineers to m...

AI Technical Summary

Problems solved by technology

For beach erosion, in addition to on-site investigation, it is a better method to use theoretical models to predict. Most of the current prediction methods are based on the transport model of mud and sand, the source of mud and sand, and the characteristics of waves and currents. Most of these methods are relatively complicated. , some parameters are difficult to determine, and it is not easy for engineers to master and use

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