The Safety Of Concrete Dam Cable Crane Under Wind Condition

Concrete dam under construction in China are mostly located in the southwest of the dry-hot valleys,dry-hot valleys of funnelling and air temperature gradient are prone to excess perennial gale,could lead to a cable crane concrete bucket produce the wind-induced effect such as length to diameter circle,sustained oscillation,makes the crane driver and warehouse surface discharge workers can’t control the ups and downs,concrete bucket easily trigger a collision accident,to bring serious challenges to the safe operation of cable crane.Therefore,according to the lifting operation characteristics of the dam cable crane under the action of wind,this paper explores the wind-induced effect of the concrete bucket of the cable crane and studies the collision damage law of the concrete bucket of the cable crane,so as to provide a theoretical basis for the safety management of the dam cable crane operation.Firstly,according to the structural characteristics of the cable crane,the force of the cable crane is analyzed and the catenary equation of the cable crane is established.On the basis of cable crane lifting sling,hanging characteristics,decomposition cable crane sling-bucket system operation process,take the resting position of the lifting object as the origin,built the three-dimensional space coordinate system,established a sling-bucket movement decomposition sling-bucket force,extracted the force analysis of sling-bucket motion,then using physics method,construction of cable machine movement model of sling-bucket system to explore the sling-bucket system speed parameters.Secondly,the operation condition of the cable crane under strong wind environment was analyzed,the airflow type of the concrete bucket of the cable crane was identified,and the influence of wind vibration on the structure of the cable crane’s sling-bucket system was determined.The force of sling-bucket system under the action of wind was decomposed,the mechanical expression of sling-bucket system was deduced,and the movement model of concrete bucket of cable crane was constructed under the effect of wind.Implicit difference method was used to optimize the calculate process and calculate the motion parameters of the cable concrete bucket.According to the structural characteristics of the cable crane,a structural model of the cable crane was built,and the wind-induced effect of the concrete bucket of the cable crane was analyzed by computer simulation.Then,take into account the surrounding environment of the concrete bucket transport,the disaster body that may collide with the concrete bucket is selected.According to the characteristics of the disaster body,the collision process of the hanging tank is described,and the collision damage model of the concrete bucket is built.According to the stress limit value of the disaster body,the safety threshold value of collision damage of the disaster body was calculated,the maximum wind level of the operation of the cable crane under the action of wind was determined,and the wind conditions allowing the cable crane to operate in the strong wind environment were investigated.Finally,according to the concrete pouring of the cable crane at Crane beach Hydropower Station,the actual situation of the project is analyzed,and the environmental parameters and speed parameters of the cable crane concrete bucket are determined.By using the method of computer simulation,describes the real wind field environment,analyzes the wind-induced effect of the concrete bucket of the cable crane,and explore the risk of damage caused by the collision of the concrete bucke of the cable crane,so as to provide suggestions for the safe operation of the cable crane in Crane beach Hydropower Station.The research results can provide aerodynamics criteria for defining the start-stop wind force level of dam cable crane lifting operation,provide safety management deduction tools for risk identification,evaluation and prevention and control of dam cable crane lifting operation,and provide construction histological basis for dam cable crane lifting operation scheduling.