Assessment and Reuse of Old Foundations

Abstract

Little is known about the foundations beneath many historic buildings and bridges. For rehabilitation projects, it is important to know the nature of the foundation system and its condition. In replacement projects, cost savings and sometimes environmental benefits can be gained from the reuse of existing foundations in new structures. In large cities, almost any new construction involves the demolition of a previous structure, which poses the problem of what to do with the old foundations. Many are too deep to be removed economically, and some are almost certain to be in the way of proposed new foundations. It is therefore a great advantage if they can be incorporated into the new design, but to do this, the engineer must have accurate information about the foundation type and depth to estimate load-bearing capacity. The authors have worked on a number of projects in the last few years that have included increasing the load on or reusing existing foundations. Information about foundation type and depth has been gained from the use of specialized nondestructive tests. In many cases, the authors also had access to archive information that included soil borings in the vicinity to correlate with test data. The methods used to assess existing foundations and allow their inclusion in the design of new foundation systems are discussed, and case histories are given for concrete drilled shafts, timber piles, and steel sheet piles.

Integrity Testing of a Platform‐Pile System Using a Sensor Array and Wavenumber Domain Analysis

“…e integrity assessments of pile foundations of bridges and wharves remain a signi cant challenge in superstructures with a lack of construction information [1,2]. Pile integrity assessments are crucial for reinforcement and reconstruction [3]. e oxidation of steel rebars, chloride-induced steel corrosion, and the resulting degradation of concrete threaten the integrity of pile systems in marine environments [4,5].…”

Evaluation of Unknown Foundations of Bridges Subjected to Scour

“…There are a number of studies on applying nondestructive testing (NDT) to obtain information about UFBs (3)(4)(5)(6)(7)(8), whereas only very few studies have used statistical, computational, or numerical solutions, or all three, to infer foundation characteristics. Risk-based approaches have been implemented by NCHRP and the Florida DOT to manage bridges with unknown foundations susceptible to scour (9)(10)(11).…”

Experimental Investigation of Grouted Helical Piers for Use in Foundation Rehabilitation

“…For example, due to degraded material engineering properties, poor or inadequate initial design, or unforeseen load conditions, the foundation of a structure may not meet current building codes. In addition, older structures may undergo structural renovation to accommodate new functionalities, which may add considerably more load demand to the original foundation (Hertlein and Walton, 2000). Additionally, when subjected to natural hazards, such as earthquakes, older foundations may not be sufficiently strong to resist the increased load demands.…”