Study On The Technology And Application Of Non Backflow High Pressure Rotary Jet Grouting In Complex Strata Along The River

High-pressure grouting is required for the reinforcement and anti-seepage treatment of complex strata along the river to ensure the engineering effect.How to take into account the engineering quality and environmental protection requirements on the premise of meeting the design requirements is a problem that needs to be solved.The existing various soft foundation reinforcement and anti-seepage technical methods,due to the constraints of construction method characteristics,stratum conditions,equipment capabilities and other constraints,it is difficult to achieve the reinforcement and anti-seepage of complex strata along the river.This paper studies a new type of grouting technology that combines the drilling and irrigating static pressure grouting method and the high-pressure rotary jet grouting method with the advantages of two grouting technologies,that is,high-pressure rotary jet composite grouting technology without back grouting.The application of non-return grouting high-pressure rotary jet composite grouting in the foundation consolidation and anti-seepage engineering of complex strata along the river can not only give full play to the respective advantages of the two methods of grouting reinforcement and anti-seepage,such as integrated drilling and grouting and high-pressure rotary jet grouting,to overcome Each has its own shortcomings,at the same time,it can achieve no grouting during the whole grouting process,so as to achieve the largest applicable stratum range and the best reinforcement and anti-seepage effect,to ensure the success rate and safety of reinforcement and anti-seepage,and to be environmentally friendly.On the basis of studying the development and application of grouting technology at home and abroad,this paper analyzes the classification and characteristics of the current conventional high-pressure rotary jet grouting technology,and summarizes the deficiencies of the existing grouting technology in the application.At present,research on high-pressure rotary jet grouting technology without back grouting is still very scarce.In order to obtain a composite grouting technology without back grouting and high pressure rotary jet grouting suitable for anti-seepage and reinforcement of complex strata along the river,this article has been carried out through theoretical analysis,field tests and engineering practice.Related research,research content and results are as follows:(1)Based on the working principle and engineering practical experience of high-pressure composite grouting without back grouting,the slurry material selection method and reasonable selection range of construction process parameters during the construction of high-pressure rotary grouting without back grouting are proposed.The design of the grouting pile type is explained and the process flow and detection method are explained in detail.(2)A series of field tests of high-pressure rotary jet grouting without back grouting were carried out.Through the field tests,the corresponding pile diameter test,standard penetration test and core drilling were used to check the test effect.According to the test data and test results,verification The applicability of the high-pressure rotary jet grouting without grouting for the reinforcement of the grouting foundation of complex formations is proposed and the construction process parameters suitable for the characteristics of similar complex formations are proposed.The specific parameters are designed as high-pressure jet grouting pressure of 25MPa and rotation speed of 20r/min,The lifting speed is 20cm/min～23cm/min.Test and analyze the grouting effect and pile diameter,and comprehensively evaluate the composite grouting effect.(3)By participating in the embankment reconstruction project along the east bank of a river in a city,the analysis and comparison of the design schemes show that,on the premise of guaranteeing the embankment foundation bearing capacity,settlement requirements and water resources environmental protection,the application of high-pressure non-returning grouting composite grouting technology is more effective.Applicable,environmentally friendly and economical.No grouting phenomenon during the whole process of grouting operation.On-site testing results after the completion of construction show that the grouting effect is good,and the pile strength and anti-seepage performance can meet the design requirements.The embankment reinforcement and anti-seepage reconstruction project proves that the high-pressure rotary jet composite grouting technology without back slurry can better solve the common difficulties of hole formation and uneven treatment when the existing conventional soft foundation treatment method is used for deep soft foundation reinforcement.Technical problems such as poor controllability and non-environmental protection can effectively improve the mechanical properties of deep and weak foundations by adopting a high-pressure composite grouting technology without return slurry.