Research And Application Of Blasting Design And Load Calculation System In Tunneling

With the development of transportation in my country,tunnel engineering is increasing day by day,and the current method of tunnel excavation is still dominated by traditional drilling and blasting methods.However,since the traditional drilling and blasting methods still have a series of problems in design,construction and vibration control,finding new blasting design methods and vibration control techniques has become an important research topic in the field of tunnel construction.In this thesis,the Visual Basic 6.0 programming language is selected as a development tool.A combination of blasting design principles and blasting load calculation theory is used to develop a tunnel blasting design and load calculation system.The dissertation relies on the Dizong tunnel in the ALTJ-2 bidding section of the Anliu Railway Station,and carries out the actual engineering application of the R & D system.On the basis of consulting a large number of blasting vibration monitoring standards and literatures,a combination of theoretical analysis,field tests,and signal analysis was used to study the blasting vibration response law and vibration reduction measures of the tunnel with a large cross-section through the building.The main work and research results of this article are as follows:(1)In terms of interface design,by reasonably arranging the relevant function buttons in Visual Basic 6.0,an operation interface with clear logic and simple operation is designed;In terms of functional design,using the structured features of the Visual Basic 6.0 programming language,the program codes for each predetermined function of the system are written to complete the input and output of each predetermined function.(2)Aiming at the engineering application of tunnel blasting design and loadcalculation system,taking the zonal tunnel DK41+945 ~ DK42+000 as the research object,a blasting scheme was designed by using this system.The actual application results show that the design and load of the tunnel blasting obtained by programming with Visual Basic 6.0 as the system development platform,combining the AutoCAD secondary development technology and the OLE array technology method,according to the functional modules described in this article.The computing system can not only achieve the predetermined function that meets the design requirements,but also form each independent module into an interconnected and well-functioning organic whole.(3)Study the propagation law of blasting seismic waves in the ground in the Dizong Tunnel.Based on the seismic wave monitoring principle and monitoring point layout principle,perform blasting vibration monitoring on the blasting scheme designed by the tunnel blasting design and load calculation system.Based on the least squares regression analysis of the vibration velocity at different blasting center distances,the blasting vibration attenuation formula of Dizong Tunnel was established,and the propagation law of blasting vibration velocity in the ground was obtained.(4)In the study of controlling the blasting vibration of a tunnel with a large cross-section through a house at a short distance,according to the on-site vibration velocity monitoring and peak vibration velocity prediction,it is found that the maximum vibration velocity generated by the existing Dizong blasting scheme does not meet the requirements of the maximum allowable vibration velocity of houses.Therefore,the existing blasting scheme is optimized by reducing the maximum single-segment charge and a variety of damping measures such as multi-stage duplex wedge groove,adding damping hole and millisecond blasting.And the blasting data before and after optimization are analyzed and compared by wavelet(packet)technology.The optimized blasting scheme realizes the safe and rapid construction of the two steps of the Dizong tunnel,which can provide a reference for similar engineering construction in the future.