Research and Application of Wall-reducing Slurry for Large Diameter Pipe Jacking in Desert Area

Abstract:

In the desert area, the stratum stability is poor and the frictional resistance is large, resulting in long distance and large diameter pipe jacking construction for a long time. The pressure loss of slurry transportation is large. It is easy to cause formation collapse and burying. The key to the smooth jacking of the large diameter pipe jacking project in the desert area is that the slurry should have good lubrication resistance and complete wall protection. Based on this key issue, indoor trials and field application studies were carried out to develop a new type of wall-reducing slurry suitable for pipe jacking in desert areas. Kaolin polymer slurry was used as the synchronous grouting slurry for the nose and the clay-free polymer slurry was used as a follow-up slurry along the line. On the basis of lubrication resistance reduction, the synchronous grouting slurry mainly focuses on the complete wall protection function, while the follow-up grouting slurry mainly highlights the characteristics of lubrication and drag reduction, so that the lubrication and drag reducing slurry system can achieve the best lubrication and wall protection functions. The new type of wall-reducing slurry for resistance reduction was developed for the first large-diameter pipe jacking project in the desert area at the top of 7～9 in the Ulan Buh desert sand-carrying water project in Inner Mongolia. The effect was good and the jacking-in work was successfully completed. The study has improved the key technologies of the pipe jacking engineering in desert areas, solved the problem of wall protection and drag reduction, and has great social and economic benefits.

Key words:long distance large diameter pipe jacking; wall protection; drag reduction; slurry; desert stratum