Vibration Monitoring And Extremum Analysis Of Prestressed Pipe Pile Construction

With the rapid development of the national transport network,pile foundation has become a mature form of construction foundation and also has a certain era value.The contemporary technology of pile foundation is a combination product between the modern technology and the traditional technology of pile foundation.Moreover,the construction equipment of prestressed pipe pile is simple,fast,low cost and easy to operate.It also plays a very important role in the pile foundation and is widely used in roads,tunnels,bridges and other pile foundation construction.Currently,many technologies of the prestressed pipe pile construction adopting the hammering method,and the majority released energy that come from the hammering is used to overcome the pile shaft friction and the earth pressure of the pile-bottom.Some noise and vibrations will come into being during this process,thus,resulting in varying degrees of impact on the surrounding rock environment and residential buildings.In this paper,the application of GPD distribution based on POT model in practical engineering has been studied by the quote of the Peak Over Threshold(POT)of extreme value theory and the combination of vibration monitoring of prestressed pipe pile construction at the east-upstream of a bridge expansion project in Guilin city.First,it should carry out the statistical analysis for the obtained part of the monitoring data,which including the analysis of the monitoring of two-way vibration rate of vibration source,the attenuation rate of the measurement points as well as the vibration effect of the residents buildings around construction region.Furthermore,the GPD distribution and GEV distribution are used for the fitting analysis of the measured data when discussing the rule of vibration attenuation.The results show that the GPD distribution is the best choice.Finally,the house vibration data is fitted by GPD distribution,and the influence of piling vibration on the velocity amplitude of the top vibration of the residents is also estimated,to determine the influence range of vibration.The results show that: based on the vibration monitoring analysis of the prestressed concrete pipe pile construction,the POT model can accurately estimate the vibration velocity extremum in the range of the confidence interval of the 95% and can reasonable work out the computational formula of the attenuation rule by the comparison of the BMM model and the POT model as well as uses the attenuation formula to determine the safe vibration distance.The research provides a reliable basis for the safety monitoring of piling construction to ensure the corresponding defensive scheme that can be made in the piling process so that reducing the loss of people’s life and property.Therefore,it has a certain theoretical value and engineering practical significance.