Comparative Analysis of Bearing Capacity of Piles Tested by Dynamic Load Test (DLT) and Pressuremeter Test (PMT)

Abstract

The paper presents the comparative analysis of several piles for different pier locations of a bridge by employing in-situ deep foundations tests and in-situ soil tests. The focus of the paper is on the presentation of the reliability of solutions obtained using the Dynamic Load Test (DLT) for in-situ tests of the bearing capacity of deep foundations – piles. The DLT test was conducted in two stages: in-situ DLT of piles and pile bearing capacity analysis using the wave theory and the method of characteristics. The signals of upward traveling force waves, obtained by in-situ DLT of piles were signal matched with the signals of the numerical nonlinear model of the dynamic pile-soil interaction. The results of DLT of pile bearing capacity are presented as componential values (regarding the pile base and the pile shaft) and as a cumulative value (total bearing capacity), so that the comparison of DLT and pressuremeter test (PMT) was conducted both according to componential and cumulative bearing capacities. Since it is not possible to strictly conduct DLT and PMT for the same settlement level, it is not possible to directly compare the bearing capacity, however the comparison was performed taking into account the bearing capacities from PMTs according to Eurocode 7. DLTs provided bearing capacities which correlate well with the PMTs results. Also, DLTs determined the corresponding elastoplastic settlement for the designed resistance of piles, which is very useful to the designers in the analysis of serviceability (settlement) of both the pier locations and of the entire bridge.