Electronic Thesis and Dissertation Repository

Thesis Format

Monograph

Degree

Master of Engineering Science

Program

Civil and Environmental Engineering

Supervisor

Dr. M. Hesham El Naggar

Abstract

Drilled shafts are conventionally used as foundations for sound walls. However, steel piles can provide faster installation and immediate utilization. The purpose of this research program is to evaluate a novel pile concept which comprises an H-pile modified to better resist typical load patterns faced by sound wall piles including lateral force and moment from wind and uplift force from adfreeze. The modifications include one or two plates welded to the pile and soil anchors (nodes) welded along the pile flange.

A full-scale pile load testing program was performed on sixteen piles which included monotonic and cyclic lateral load tests and uplift load tests. A numerical model was developed and validated from the experimental results which was then used to explore the effect of plate dimensions and the soil type on a pile’s lateral capacity. A second numerical model was developed to extend the cyclic lateral load analysis to simulate higher loads and more load cycles.

The test results showed that the plate greatly increased lateral capacity and the parametric study demonstrated that widening the plate is more efficient for increasing lateral capacity than lengthening it. The cyclic tests and modelling revealed that the lateral stiffness of the piles remains approximately constant within 100 cycles and the pile is not expected to exceed deflection limits after 1000 cycles of the design load. The uplift load tests concluded that adding nodes decreased the uplift capacity of H-piles. It was observed that the installation quality of the piles directly affected pile capacity.

Summary for Lay Audience

Sound walls are utilized for reducing noise caused by traffic or industrial and commercial activities. Drilled shafts are conventionally used as foundations for sound walls; however, steel piles can provide faster installation and immediate utilization. A novel pile concept was developed which comprises an H-pile modified to better resist typical load patterns faced by sound wall piles, which may include lateral force and moment from wind and uplift force occurring in regions where soil experiences seasonal freeze and thaw. The modifications include one or two plates welded to the pile and soil anchors (nodes) welded along the pile flange. The main objective of this research program is to assess the suitability of these modifications for sound wall applications.

A full-scale pile load testing program was performed on fourteen steel piles installed with vibratory driving and two drilled shafts. The testing program included static and cyclic lateral load tests and uplift load tests. A numerical model was developed for static laterally loaded piles which was validated using the experimental results and then used to simulate the pile with different plate dimensions and installed in a range of practical soil conditions. A second numerical model was developed to extend the cyclic lateral load analysis to include higher loads and more load cycles.

The results showed that adding a plate can greatly increase its lateral load capacity. The corresponding numerical model demonstrated that widening the plate is typically more efficient for increasing the pile’s lateral capacity than lengthening it. The cyclic lateral load tests revealed that pile deflection remains approximately constant within 100 cycles. The cyclic model demonstrated that the pile does not exceed deflection limits after 1000 cycles of the maximum anticipated lateral load. The uplift load tests concluded that adding nodes decreased the uplift capacity of H-piles. Analyzing the load transferred from the pile to the soil showed that the portion of the pile where nodes exist had significantly reduced shaft resistance due to disturbance of the clay occurring during installation. It was observed that the installation quality of the piles directly affected their uplift and lateral load capacity.

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