Study On Key Control Indexes Of Chemical Grouting Technology Used In Pre-curing Of Subgrade

With the development of road traffic in China,the impact of road subgrade disease is becoming more and more important.Therefore,it is imminent to carry out the pre curing of the subgrade and restore the service performance of the subgrade.Chemical grouting is the main measure for the treatment or maintenance of subgrade diseases because of its advantages of small damage to the subgrade structure and strong pertinence.However,the current design and construction are mostly based on experience,which hinders the rational application of the technology.Therefore,it is urgent to develop the relevant research,establish a perfect index system and guide the actual production.On the basis of references and engineering practice,the characteristics of chemical grouting technology are analyzed and summarized in this paper.First of all,this paper introduces the research status of chemical grouting technology and roadbed pre curing at home and abroad,and summarizes the construction technology of chemical grouting material and chemical grouting.On the basis of this,the discriminant method of chemical grouting applicability is introduced.Secondly,the control index of chemical grouting technology is analyzed and summarized in detail,and the calculation method of each control index is analyzed in detail.And the calculation method of composite subgrade replacement rate after grouting is put forward through theoretical analysis.After calculating the replacement rate of compound roadbed after grouting,the effective equivalent radius of grouting should be converted to the equivalent radius through the principle of equivalent radius transformation.Then the calculation method of replacement rate is determined based on the intersection way of grouting equivalent column and the hole form of grouting hole.On the basis of summarizing the characteristics of roadbed diseases and referring to the concept of pavement pre maintenance,we put forward the understanding of the scope of pre maintenance for roadbed,and the subgrade settlement,subgrade strength and the roadbed slippage of roadbed slippage are all belong to the pre maintenance scope of roadbed.On the maintenance of the minor repairs,repair,overhaul and renovation of the scope of the specific division of roadbed repair maintenance to range in general.Based on the analysis of control index of pre maintenance for different roadbed diseases,a design and calculation method of control index system of chemical grouting for different roadbed diseases is established.In the pre curing design calculation of chemical grouting for subgrade settlement,the key is to calculate the replacement rate of resilient modulus which is required by specification after analyzing the resilient modulus of composite roadbed after grouting,and then determine the remaining control indicators,and the settlement calculation method of the built road has been improved..For the pre maintenance treatment of subgrade insufficient bearing capacity,the key is to calculate the replacement rate of compression modulus to meet the standard requirement by analyzing the compression modulus of composite roadbed after grouting,and then determine the remaining control indicators.For the pre maintenance treatment of roadbed instability,the key is to calculate the replacement rate that satisfies the standard stability factor or the equivalent radius and hole spacing of grouting hole after analyzing the stability of composite roadbed after grouting,and then find out other grouting indexes.