In recent years, the technique of high pressure injection mixing has been increasingly employed for various purposes such as stabilizing the ground neighboring the existing facilities,construction of soil cement block around pile toe, and so forth.Stabilized body is required to have designated shape and size,as well as strength, which are usually ensured through site management indirectly.It is therefore important to understand the relationship among the injection method,physical and strength properties of soil,and size of ground excavated and mixed by injected fluid.
A few techniques of high pressure injection mixing provide the evaluation method of excavated and mixed range. However,these evaluation methods can be used only for each technique,because they include effects of innovative device of the technique implicitly.On the other hand,Modoni et al.(2006) developed a theoretical model for evaluation of size of ground cut and eroded by jet grouting from a single nozzle,based on understanding of the interaction between injected fluid and soil.This model can be expected wide range applicability such as water injection and injection from plural nozzles,because it includes characteristics of injected fluid and soil as explicit parameters.
In this paper,improvement of applicability of Modoni’s evaluation method is discussed for performance evaluation of excavation and mixing by plural injection nozzles based on model and in-situ tests.