Part 2: SMI Concrete Flat Plate and Site Safety Demolition Plan Peer Review

This four-part series (Part 1, STRUCTURE, November 19) discusses how the collapse of a building during a demolition operation in Philadelphia in 2013, which resulted in several fatalities, led to the enactment of a City Ordinance to prevent similar future calamities. As a result of the Ordinance, the author became involved with the structural investigation, review of the Site Safety Demolition Plan, and Demolition Special Inspections associated with the adaptive reuse of the Apex Hosiery Company Building located in Philadelphia. …

Part 1: History of the Philadelphia Demolition Ordinance and the Apex Hosiery Building

This four-part series discusses how the collapse of a building during a demolition operation in Philadelphia in 2013, which resulted in several fatalities, led to enactment of a City Ordinance to prevent similar future calamities. As a result of the Ordinance, the author became involved with the structural investigation, review of the Site Safety Demolition Plan, and Demolition Special Inspections associated with the adaptive reuse of the Apex Hosiery Company Building located in Philadelphia. …

The thermal factor, C_t, in the American Society of Civil Engineers’ Minimum Design Loads for Buildings and Other Structures, ASCE 7-16, is intended to account for expected changes in roof snow loads due to heat flow through the roof. As one might expect, for poorly insulated structures with large amounts of thermal energy available to melt roof snow, the C_t factor is low (C_t = 0.85 for certain greenhouses) while, for very well insulated structures, the C_t factor is high (C_t = 1.30 for freezer buildings). …

Rehabilitating the Culver Line Viaduct with Composites

When it comes to rehabilitating bridges, an increasingly attractive answer is composite materials. Composites are made from two or more distinct materials that, when combined, produce a stronger and better material offering lighter weight, corrosion resistance, versatility, and overall cost-effectiveness. These qualities are ideal for maintaining fragile historical bridges, safely installing prefabricated decking, and curbing long-term maintenance needs. Perhaps no North American project demonstrates the benefits of rehabilitating with composites more than that of the New York Subway System’s Culver Line Viaduct. …

Part 2: Investigation, Repair, and Rehabilitation

Part 1 of this 2-part series (STRUCTURE, June 2018) addressed structural behavior and assessment methods. Part 2 focuses on analysis and repair options. …

Part 1: Investigation, Repair, and Rehabilitation

Part 1 of this 2-part article addresses structural behavior and assessment methods. Part 2 will focus on analysis and repair options.

Due to increasing costs and restrictions associated with redevelopment (replacement) of existing buildings, as well as municipal initiatives geared to promote the preservation of the existing building stock, repair and rehabilitation of existing buildings have become economically and politically attractive options for property owners. …

Repair Options and Replacement Materials

The case to replace terra cotta in-kind with the integration of a corrosion mitigation system, rather than full-scale replacement or replacement with an imitation material, provides clients with a durable, long-term repair and restoration program that retains the original building fabric. This article discusses the history of architectural terra cotta and various repair options in lieu of stripping and replacing. …

Heavy snow accumulations on the roof of an elementary school in central Oregon in January 2017 caused structural damage to six wood roof trusses that span approximately 75 feet. The trusses were found to have some bolted connection failures at heel plates, as well as three split and fractured web elements also associated with their bolted connections. Snow load on the roof was reportedly around 40 pounds per square foot (psf), while the trusses were initially designed for 30 psf. …