The Mechanism And The Project Application Of Foundation Pit Chemical Grouting Shoring In Loess Area

The slope stability of foundation pit in the loess area has caught people's attention. How to find a kind of economy, rational support pattern, it's one of a important content has been studied by geotechnical engineer. This paper base on the exploration and practice of consolidating method in reinforce soil. From the angle of chemistry seeks one kind of the material applying to the loess area foundation pit slope support by the experiment of indoor and spot. This has important science significance and application study value to resolve the stability of foundation pit in the loess area and remove the loess collapse.At the beginning of the paper has introduced a kind of chemical materials, according to the principle of practicality and economy, having chosen final water glass grouting material. Frequently-used materials carry out primary election by pure solution indoor experiment and remove the unsatisfying material of chemical grouting. The surplus materials carry out excellent selection by the indoor experiments of sand grouting and loess grouting, and finally ascertain ultimately material, namely water glass-fluosilicic acid. By the derivation form Darcy flow formula, reachs the formula being suitable to the loess area chemical grouting radius calculation formula, and summing up in driving force viscosity calculation. Chemical grouting strengthening mechanism has been carried out analysis, and explains the principle of chemical grouting handling chemistry grouting loess collapse. The strengthened and unstrengthened soil carry on loess collapse experiment, and the result of experiment has proven chemical grouting eliminating the collapse of collapsing loess. Carrying on the sand gallery chemical grouting and the loess boreholes chemical grouting experiment, and carrying on the experiment of density, moisture, seepage and shear for the unstrengthened and strengthened soil. The experiment has proven the osmotic coefficient of sand and loess sample after grouting reduce, and shear strength has promoted. At the same time, study the law of loess shear strength and the moisture content at the front and back. At last, make use of three modules SLOPE/W, SEEP/W and SIGMA/W in commerce software Geo-slope to carry on numerical simulation calculation in the foundation pit.Main research result: (1)Sum up out the calculating formula of the kinetic viscosity of seriflux and time by experiment. (2)Deduce out the formula calculating of loess chemistry grouting radius estimating. (3)Field trial has certificated that chemistry grouting has eliminated the collapse of loess. (4)The chemical grouting experiment in spot sand and loess have certificated that chemical grouting has fairly good strengthening effect for sand and loess.