MPC Research Reports |
Title: | Development of LRFD Recommendations of Driven Piles on Intermediate Geomaterials |
Authors: | Kam Ng, Nafis Masud, Opeyemi Oluwatuyi, and Shaun Wulff |
University: | University of Wyoming |
Publication Date: | Aug 2022 |
Report #: | MPC-22-478 |
Project #: | MPC-651 |
TRID #: | 01863710 |
Keywords: | bridges, geotechnical engineering, load and resistance factor design, pile foundations, shale, soft rock, statistical analysis |
This study aims to improve the efficiency of driven piles in intermediate geomaterials (IGMs) to increase the reliability of pile foundations for bridge structures. Test pile data collected from the seven state DOTs and total 223 pile load test data are evaluated to provide recommendations for driven piles in IGMs. A classification method to differentiate fine-grained soil from fine-grained IGMs (FG-IGMs) is established. Shales are classified depending on their weathering conditions, mechanical properties, and measured pile resistances. Newly static analysis (SA) methods for predicting unit shaft resistance (qs) and unit end bearing (qb) are proposed and validated for both FG-IGMs and shales. The statistical assessment concludes that the proposed SA methods provide more accurate predictions of qs and qb and yield higher LRFD resistance factors than those of the existing SA methods. A back-calculation procedure is adopted to yield recommended dynamic parameters for shale, which are incorporated into a proposed Wave Equation Analysis Program (WEAP) method. An economic study reveals that the proposed WEAP method yields the least excess steel weight, on average, during construction, which will alleviate construction challenges encountered in the current practice, such as higher construction cost and longer construction duration.
Ng, Kam, Nafis Masud, Opeyemi Oluwatuyi, and Shaun Wulff. Development of LRFD Recommendations of Driven Piles on Intermediate Geomaterials, MPC-22-478. North Dakota State University - Upper Great Plains Transportation Institute, Fargo: Mountain-Plains Consortium, 2022.