Research On Anti-segregation Of Concrete Safety Transportation In Ultra-high Vertical Distance Deep Shaft

As domestic and foreign mines enter the deep mining stage,the traditional delivery methods such as buckets are used to transport concrete downwards,and its transportation effect has been unable to meet the construction schedule requirements of mine construction.Sliding pipe transportation enables concrete to overcome friction and air resistance under its own gravity,and moves down the sliding pipe.It has the advantages of fast velocity and continuous pouring.It will become the main way of concrete transportation in deep shafts.In the construction of deep shafts,after a certain vertical distance of self-sliding transportation,the slurry and aggregate have different material shapes and different running velocity,which leads to segregation,which makes it difficult to meet the design requirements of the forming shaft support quality.Therefore,it is of great significance to carry out exploratory research on antisegregation of ultra-high vertical-depth deep shaft concrete self-slip transport to enhance the construction level of deep shafts over 1,000 kilometers and ensure the stability of deep shaft structures.The thesis is one of the main contents of the National Key R & D Program Topic 2 "Key Technologies and Equipment for Efficient Driving and Formation of Deep Vertical Shafts in Metal Mine"(No.2016YFC0600802)"Optimization of Wear-Reducing and Anti-Segregation Concrete Transportation Process" Subject to the existing "Construction Standards for Coal Mine Roadway Engineering",it is impossible to carry out on-site test work before the formation of a new technical standard specification for a thousand-meter-deep well.The thesis combines field investigation,theoretical analysis,numerical simulation and other methods to carry out the anti-segregation research of the concrete self-sliding conveying process,and proposes the corresponding segregation control method.The main work of the paper is as follows:(1)Introduce the static and dynamic segregation forms of concrete,analyze the main influencing factors of concrete segregation during the self-sliding transportation process,such as material factors,pipeline system factors and anti-segregation devices.(2)A calculation model of the relative velocity between aggregate and slurry was constructed to reveal the internal mechanism of concrete segregation,to study the effect mechanism of different slurry rheological parameters and aggregate properties on the relative velocity,and to analyze the velocity of aggregate during the self-sliding transportation process law of change.(3)Using slurry speed,relative speed and wear as indicators,solve the speed-lowering mixing efficiency of different anti-segregation devices,and select the best device suitable for the deep vertical shaft slide tube system;through the orthogonal test design scheme,analyze different structures The influence of parameters on the index optimizes the structural parameters of the device.(4)Analyze the movement law of concrete in the full pipe flow state to determine the vertical distance of segregation;use this as the layout distance,put forward the scheme of intermittently installing anti-segregation device for the slide pipe,which can realize continuous and anti-segregation transportation;in the existing technology Under the premise,control measures such as fresh concrete preparation,pipeline layout and conveying technology are proposed to achieve safe conveying of concrete during self-sliding conveying.The research results provide a certain prospective guidance for the design of the slide pipe system,and it is hoped to promote the development of deep shaft construction technology and realize the safe and rapid completion of deep shaft.