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. / text

This thesis focuses on the finite element modeling and analysis of wood shoring towers used by Urban Search and Rescue (US&R) teams during emergency response situations. These shores are constructed on site to provide temporary stabilization to a damaged structure. A high demand exists for experimental testing of the performance of these shores under non-ideal loading conditions, and for possible design modifications that could improve their overall behavior. To respond to this need, a total of thirteen vertical shores of the type laced post (LP) and plywood laced post (PLP) were constructed and tested at the Ferguson Structural Engineering Laboratory (FSEL) in Austin, Texas. The tests conducted on these shores aimed to investigate their performance under purely vertical load as well as various combinations of vertical and lateral loads. Finite element models for eight of the shores tested at FSEL were built and analyzed in Abaqus to compare the computed results with the actual linear elastic response of the shores. Material properties for the posts in each shore were obtained through further material testing at the conclusion of each shore test. Shore members were assumed to be isotropic. Solid elements were used to model each member, and Cartesian connector elements with a predefined nonlinear stiffness were used to model each nail. In general, the vertical load-displacement response computed from Abaqus exhibited good agreement with the laboratory results for the linear elastic range. The same general modeling scheme was then used to make design changes to the original shores based on observations gained during testing as well as modeling. Each design change was modeled, analyzed, and then compared with the computed results from the original shore design as well as the other design changes. The basis for evaluating the effectiveness of a given shore design involved comparing the bending moment diagrams for each post and the maximum first story nail slips (connector displacements). Recommendations were made for improved shore designs to be verified by experimental testing. / text