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.

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

The feasibility of using pebble bed as bearing stratum of PHC pipe pile;

Based on the analysis of ground condition of hydrogeology and engineering geology,the design parameters of the underground reservoir inter-seepage dam in pebble bed are studied.

Being a typical long span,shallow cover tunnel of flattened profile,the West Tunnel of Maoshan along Nanjing and Changzhou Highway is situated on the incline of re- sidual deposit of pebble/gravel strata.

By the analysis of present drilling ways,and according to the characteristics of gravel strata,application feasibility is put forward for DTH hammer concentric simultaneous casing drilling tool in gravel strata,and analysis are made on the structure principle and characteristic of drilling tool.

Through applying downhole hammer concentric simultaneous casing drilling method,the difficulties that drill in gravel strata are solved out fundamentally,the authors consider downhole hammer concentric simultaneous casing drilling is an effective way for gravel beds in combination with a case of rock-soil engineering survey in Duyun Cit