Testing of Emergency Wood Shoring Towers for use in Urban Search and Rescue Operations

Emergency wood shoring towers are utilized by Urban Search & Rescue (US&R) specialists to temporarily stabilize a damaged structure. Standardized designs for wood shoring towers have been developed and are published in manuals for use in US&R operations. These designs have been validated largely through past testing under simplified vertical loading. Research was conducted to provide additional insight into the performance of two common types of shores, the laced post (LP) shore and the plywood laced post (PLP) shore, under non-ideal (other than vertical) loading scenarios. Shores were tested under vertical load only, under lateral load only, and under combined vertical and lateral load. For lateral loading, some shores were tested under monotonic lateral load (lateral load applied in one direction only) and some were tested under cyclic lateral loading. Each specimen was tested to failure, and the documented capacity compared to the FEMA specified shore design capacity. Early warning signs of shore distress known as “fuses” characterized by audible cracking sounds, cupping of the wedges, or cracking of members were also evaluated during testing for their effectiveness and consistency. The performances of the laced post and plywood laced post shores were compared and recommendations made.