Analysis On Two Methods Of Representing Earth-rock Dam Compaction Compactness

Since the water resources in the west of China has been developed,earth-rock dam catches engineers’ attention.Higher requirement was put forward to earth-rock dam quality.A very important thing to earth-rock quality is compaction compactness.The conventional rolling method has the method of controlling the rolling process,such as controlling the running speed of the rolling machine and the magnitude of the rolling excitation force.Such parameters are controlled by the construction personnel to operate the rolling mill,mainly by the construction personnel of the construction experience and on-site operating status of the decision,not easy to objective control.There are also methods in the conventional method of control after the end of rolling,such as the end of rolling after excavation of soil detection density,the degree of compliance is qualified,this method in the rolling through the experimental operation after the results,digging soil The body test process cumbersome,the dam has a certain damage to the point of the surface reflects the whole body of the dam compact compaction situation is not comprehensive;the other side of the test pit test earth and rock dam compacted,is a postcontrol,feedback on the compactness of the feedback lag,There is not timely characteristics,it is necessary to develop real-time control of vibration rolling quality of the construction method.From the predecessor of the results of CMV as the starting point,the use of roller rolling times increased,dam material densification,vibration wheel vibration acceleration signal in the high frequency components increased,the amplitude of the law,the second harmonic amplitude and the fundamental amplitude The ratio(and then appropriate to enlarge a certain number)as the index CV,characterization of dam material compactness.Calculate the CV first to the vibration acceleration signal Fourier transform,and then find the fundamental and second harmonic amplitude,the last second harmonic amplitude and the ratio of the fundamental amplitude CV.In the process of analyzing the vibration acceleration data,it is found that the noise has interference to the vibration acceleration signal,and the interference has an influence on the characterization of CV.In order to solve the problem of noise in CV research,the second method is studied.Method to characterize the dam compactness.The filtering method filters the high frequency components with the cutoff frequency as the boundary of the vibration acceleration signal,and retains the components below the cutoff frequency.The two methods are used to calculate the vibration data of the measured vibration.The two methods are used to characterize the use of the compactness of the dam.Finally,two methods can be used to characterize the rolling density of the dam,Increase,the dam material becomes compact,the stiffness of the dam material becomes larger,the energy returned to the vibrating wheel increases,the harmonic component of the vibration signal increases,the amplitude increases,and the index CV calculated by the two methods increases.The method can characterize the compactness of the dam,but the filtering method decays part of the energy by filtering,so the index value calculated by the filtering method is low.