Study On The Influencing Factors Of The Interval Time Between Adjacent Bands In The Pouring Silo Of Baihetan Dam

In the construction of high arch dams,the length of the pouring interval directly affects the degree of interlayer bonding.The longer the concrete pouring interval,the greater the probability of occurrence of cold joints,and the greater the impact on construction quality.If the interval time is longer,while directly extending the pouring duration,it is also necessary to carry out temperature control measures such as water spraying and moisturizing on the warehouse surface,covering the thermal insulation blanket,and performing secondary vibration on the old concrete,which may cause delays in the construction progress.The interval is affected by many factors,and the randomness is strong,it is difficult to accurately grasp the changing law of the interval time.Therefore,it is necessary to study the influencing factors of the pouring interval of high arch dams,with a view to fine management of influencing factors and precise control of pouring interval,improve the level of construction quality and schedule control during the pouring process,and provide guidance for the subsequent construction operations of the pouring warehouse.With the continuous maturity of dam safety monitoring technology and the requirement of short-frequency continuous monitoring,the Baihetan Dam has accumulated a large amount of real-time monitoring data during the construction period.This article combines the Baihetan project example,based on the monitoring data,the interval time between adjacent strips and their influencing factors were analyzed.Main research contents are as follows:Firstly,construct a pouring warehouse database based on real-time construction data.For the two processes of cutting and vibrating,analyze the interval time between adjacent stripes from horizontal and vertical,from the perspective of intuitive data,look for the problems in the interval control in the past pouring process.Secondly,for the specific pouring warehouse,the qualitative and quantitative analysis of the three influencing factors of construction machinery,air temperature and wind speed.Among them,the research on the deployment of construction machinery shows that: The intermittent operation during the casting of the cable machine directly affects the interval time,and compared with three half cable machines feeding,four cable machines have more feeding interruptions,which has a greater impact on the interval time.At the same time,it was found that the proportion of abnormal values in the interval time including the maintenance interval of the cable machine is large,therefore,reasonable planning should be done in advance.Thirdly,use the grey correlation analysis method to rank the influence degree of the influencing factors,and use statistical analysis methods to build regression models,the results show that the model can play a role in predicting the approximate interval time.At the same time,using whether the pouring temperature exceeds the standard as a judgment index,the model can be used to judge the reasonable control range of the interval time.The research results show that: the correlation of wind speed is high,indicating that the interval time is greatly affected by wind speed,and with the acceleration of wind speed,the interval time is gradually increasing.As the temperature rises,the interval rises quickly,then slowly decreases and gradually stabilizes.In addition,the interval between wind speed within(2,3] m/s and temperature within(20,30] ℃ should be controlled,The data of pouring temperature exceeding the standard set appears in this range,at this time,the interval time should be strictly controlled below 2 hours.