Static pile load tests (SPLTs) have been carried out in conjunction with high-strain dynamic pile testing (PDA) at three different sites to investigate the pile capacity in support of the structural design of two buildings and a bridge. Conducting the pile load testing was considered an investment to achieve more cost-effective foundation designs for current and future projects. The Canadian Highway Bridge Design Code and the National Building Code of Canada permit higher geotechnical resistance factors when static or dynamic pile load tests are conducted to reduce the geotechnical uncertainty. In each case the owners found value in undertaking the load tests in order to be able to use higher geotechnical resistance factors as outlined in the Canadian Highway Bridge Design Code and the National Building Code of Canada.

In eastern Ontario a very common deep foundation type is the use of driven steel piles, either H-piles or pipe piles, driven to refusal on bedrock. In some cases, the site conditions require pile lengths that can easily be over 25 m, representing a material cost of the overall structure. For three case histories presented, the authors proposed and were retained to complete pile load tests to support a 50 percent increase in the factored Ultimate Limit States (ULS) axial geotechnical pile capacity. In all three cases both dynamic (PDA) and static load tests were completed, and the results supported much higher pile capacities than originally anticipated otherwise.

In view of the results of the SPLT and PDA tests, the paper also discusses the appropriateness of the current geotechnical resistance factors for piles driven to refusal on sound bedrock where in all the cases undertaken the structural capacity of the pile was the limiting factor.

As one of the major deep foundation type, driven steel pile (DSP) is widely used in all construction projects in Canada. Especially in rural northern Alberta areas where concrete supply is not accessible in a cost-effective manner, the DSP foundation is highly preferred by heavy industrial development such as oil and gas related facilities.

For driven steel pile set in the fine-grained soils, a significant pile-soil setup (pile capacity gain) is expected due to excessive pore water pressure dissipation after the pile installations. In the field, pile appeared to have a much lower capacity at the end of the installation compared to long-term performance. In a fast-paced construction environment, the time cost to wait and verify the pile long-term capacity is not desired. To proceed with the upper structure construction without any delay, a reasonable prediction of the DSP setup is required. However, a very limited study has been done for the rate of pore water pressure dissipation in clayey soils.

This study is aimed to provide a case study of the pile setup effect of DSP set in Edmonton Clay Till by using the finite element method compared to the field observation data. A numerical model is being built to allow foundation engineer to assess the pile setup behavior with available soil testing results and reasonable assumptions.

Il est important pour les ingénieurs en géotechnique et les entrepreneurs de connaître les conditions d'eau souterraine pour toute excavation temporaire ou permanente. Les informations souhaitées incluent les valeurs de la conductivité hydraulique, les débits de pompage anticipés, les rabattements anticipés, les risques d'instabilité mécanique. Cependant, les informations recueillies sont souvent limitées. L'étude géotechnique d'un projet est limitée généralement à quelques forages dans l'emprise du projet. Les informations tirées de cette étude locale peuvent être complétées par des informations publiques tirées des banques de données des puits. Ces banques renferment de nombreuses données trop peu exploitées en géotechnique. L'article fournit des exemples de données statistiques, relativement faciles à extraire, sur les débits de pompage dans les puits au voisinage d'un futur projet. Il donne aussi des informations sur la performance relative de diverses techniques de forage des puits, une performance qui varie selon le type de roc aquifère. On montre ainsi l'utilité des banques publiques de données sur les puits pour les professionnels et surtout les entrepreneurs qui doivent planifier, installer et opérer des systèmes d'assèchement des excavations.

Construction of buried infrastructure, e.g. pipelines, storm drains, power transmission cables, etc., is commonly initiated by excavation or trenching. Excavation or trenching is inherently dangerous; therefore, it is important to adhere to guidelines to help prevent collapse and mitigate injuries or damage to adjacent properties. This is especially true for unsupported vertical cuts. Most excavation or trenching operations involve soils above the water table where the soil type and the influence of matric suction (i.e. negative pore-water pressure) are often overlooked in geotechnical engineering practice. In this study, laboratory tests are conducted to investigate the stability of an unsupported vertical cut in the vadose zone using a specially designed large-scale soil tank (B × L × H = 1.5 m × 2 m × 2.4 m) while taking into account the influence of matric suction. The soil tank is filled with engineered sand and has provisions to simulate both saturated and unsaturated conditions by controlling the level of water. The experimentally determined maximum depth of an unsupported vertical cut (i.e. critical height) is compared with that obtained using a simple-to-apply, semi-empirical mathematical model. Additionally, a detailed description of the soil tank is presented.