Mix Proportion Test Of Grouting Fluid And Application In The Indoor Model Test

In recent years, with the popularization and application of static pile of northern regions and found that static pile is difficult to cross medium thickness sand and hard soil rivers sedimentary in river and lake faces interaction, giving s mall piling force, pressuring pile does not go on, increasing pressure, breaking the pile easily ;using common methods for subsidiary sinking pile at present such as water jet and dig indigenous, reducing compaction effect ; When the pile tip breaks in the sand bearing stratum, because of sand "enhanced" and "relaxation" effect, loading, the tip resistance increases, unloading, it decreases, which has brought two main issues that bearing capacity instability and control construction quality difficultly . Sometimes, in order to overcome these shortcomings to use bored piles and post-grouting pile, but bored piles are difficult to drilling in sand stratum, drill pipe sticking and dropping often appears; Hole wall is not easy to maintain, sloughing is easily, causing to hole shrinkage,pit mud,segregation,broken pile, so that the pile quality cannot ensure; And the most important is that bored piles not only without soil compaction effects, reduce the pile side resistance caused by thick mud hull, but also fail to eliminate sand liquefaction and loess collapsibility; Although the post-grouting pile can remove a hidden danger of pile bottom sediment of bored piles ,improve bearing capacity and meet the deformation of pile, but bearing capacity of bored piles is far less than pile shaft, causing a huge waste.So we think of the method of synchronous grouting static pressure precast driving pile ,which belongs to the field of reinforced concrete precast driving pile construction technology in construction field, the main technical features : preparing two kinds of slurry in advance, static piles and grouting processes simultaneity operation: injecting pile shaft slurry simultaneously in the pile pressing process, pile tip slurry is continue implanted after that the pile tip reached to the design depth, so that the formation of pile tip expanded head; this method can reduce construction costs and improve the quality of construction; it overcomes the shortcomings of pile driving difficulty for static pressure pile, the method not only reduce the dynamic friction and improve the efficiency of piling, but also to improve lateral pile shaft resistance and pile tip resistance, thus ensure driving depth and pile quality, reduce the pressure pile driver tonnage, improve construction efficiency, thus extending the scope of application of static pile and reduce project cost.Simulated establishment synchronous static pressure grouting pile model in door will be used, model characters were studied ,providing theoretical research for pile driving method, further enhance understanding of function principles and make preparation for lateral generalization.