CLIENT: Apria Inc.
PROJECT DESCRIPTION:
PRI completed a combined geotechnical and hydrogeological investigation to support the design of a proposed six-storey mixed-use development — 60 residential units over ground-floor retail with two underground parking levels — on a roughly 1,410 m² urban infill site south of Lakeshore Boulevard West. The program characterized the overburden and shale/limestone bedrock, established the groundwater regime and dewatering requirements, and delivered foundation, excavation, shoring and groundwater-control recommendations for redevelopment of the former auto-service property.
CHALLENGE:
The constrained urban infill site abutted existing buildings yet required a two-level basement excavated into shale/limestone bedrock beneath a shallow groundwater table. Interbedded limestone, highly variable rock quality (RQD 0–79%), and groundwater chemistry exceeding City of Toronto sewer-discharge limits added significant excavation, shoring and dewatering complexity.
APPROACH:
PRI delivered an integrated geotechnical, hydrogeological and — with D.M. Wills — environmental program, combining SPT drilling, rock coring and Point Load testing with three months of groundwater monitoring and slug testing. The data were used to model dewatering volumes, define foundation and shoring parameters, and benchmark groundwater quality against municipal discharge criteria.
OUTCOME:
The work confirmed competent bedrock suitable for shallow/raft foundations at 750 kPa (ULS), defined secant-pile shoring and rock-anchor parameters for excavating next to neighbouring buildings, and quantified short- and long-term dewatering rates and permitting requirements (PTTW/EASR). Results were issued in signed Geotechnical and Hydrogeological Investigation reports supporting the City of Toronto SPA/rezoning submission.