Main problems and determination of foundation strength of pier of the second Nanjing bridge

The rock strength is one of the main problems related to the pier foundation of the second Nanjing bridge across the Changjiang River. Poor cementation of conglomerate with sandy conglomerate and wide range of gravel diameters make it difficult to sample and to test by the conventional methods. A thorough geological investigation having been carried out and field tests conducted some mechanical parameters are suggested in this paper. Our work has provided a dependable basis for optimization design of the bridge piers.