Based on site tests,this paper discusses the effect of pressure grouting under pile s tip in cobble layer and analyzed its economical and social benefit.

New technology of pressure grouting under pile tip at cobble layer can largely improve pile bearing capacity and reduce its settlement.

Field test study of methods for supporting large-section inclined shaft in gravel layer

From consolidating similar past case studies with regards to the problems encountered during construction phase, this article is able to provide an important point of view on shield tunnel design in gravel layer.

The application of pipe-jacking in sand-pebble layer of Chengdu Leshan sewage control engineering is introduced,including equipment selections and construction techniques,and the reason of pipe-jacking with upward-deflection is analyzed.

Some problems about post-grouting design of bored pile inserted to boulder bed in soft foundation;

Taking measures as making guide holes in pile sites,embedding PVC tubes in the boulder bed,setting proper jetting pressure,repeating jetting,controlling the quality of cement mortar and jetting quantity and so on,ensured the quality of chemical churning piles in boulder bed and effected the seepage control.

Optimization design of support scheme for a shallow tunnel in gravel deposits;