Research Of Grouting Consolidation Technology In Sandy Gravel Ground By Undercutting Under Shallow Cover Tunnel Near Bridge Pile

The aims of this paper are for the problems of Beijing subway of No.4 line 12 objects in sandy gravel ground by undercutting under shallow cover tunnel near bridge pile. The paper adopts many kinds of research means, such as theoretical analysis, grouting simulation tests and numerical simulation etc. In order to make it all-round, systematic and deep research on the grouting technology when excavating tunnel in the sandy gravel ground, it gets the following results.1. Applied pile-soil action two dimensions the flexible model analyzed the influence mechanism and main influence factor, combining Beijing undercutting under shallow cover over the bridge pile construction experience, put forward Xizhimen the control standard and the bridge pile Debao footbridge to sink to decline of main control measure.2. By heritage index, indoor experiment and the spot investigation, the rock characteristic, class degree and mechanics characteristics are analyzed; and the bore technique and protect the wall technique sand gravel ground are detailed, and grouting material carrying in research towards is suitable for ground to grouting theories and.3. To applied design process that retreats deep bore of type to note the grouting technique in the sand gravel ground, the liquid note the grouting work method characteristics to carry on a research, to note the grouting parameter such as grouting scope, grouting project, grouting pressure, grouting discharge and the grouting bore to set out...etc. it succeed to crossing Debao footbridge.4. Aim at the bad ground condition transforming a standard strict circumstance of control, forward type deep bore grouting technique is selected; adopted the cement grouting material, the sand gravel ground is solved; protecting wall technique is a hard nut to crack. The application numerical imitation method estimates the sink of bridge decline. The data to express that grouting project is successful.The results of above research are gonging to provide a reference and draw lessons for similar engineering aftertime.