Expert Witness, Litigation Support

Due the spectrum of knowledge and capacity of the WIN Structural team in analytical work, problem solving, research and development plus the knowledge of various structural materials and systems including the state-of-the-art technology and science, WIN engineers offer litigation support and expert witness consultancy to investigate structural failure, collapse and catastrophes.

Finite Element Analysis

PROJECT: 88 South Broadway New condominium building partial collapse, Millbrae, CA

Study of the pre-stressed concrete mat foundation following the local collapse and columns punching shear failure through the building. Investigated the possibility of design defects and poor design sequencing of pre-stressing and poor detailing of drawings. Also, investigated the poor construction means and methods during the erection of the building.

WIN team used advanced tools such a 3-D modeling in solid works for simulation of the cause to the partial collapse by laying out all the structural elements with their finest details in 3-D to support the litigation case, explain the problem visually and convince the opponent’s team and the jury.

WIN team member attended depositions, arbitration and testified on many of these cases. Witnessed mediation session and prepared reports for causation and defects.

Expert Witness

PROJECT: World Trade Center One and Two (WTC1, 2 and 7) Investigation of the Collapse, NIST, New York City, NY

WIN members participated in the study of the cause of exterior columns collapse mechanism under high temperature loading. Performed a second order non-linear buckling analysis of the tower columns under elevated temperature; built a finite element model of a nine-story column using ANSYS software with input of break elements. The model consisted of the splices modeled as contact elements and tied with pre-tensioned bolts. The models incorporated both geometric and material non-linearity at elevated temperature. WIN team member was recognized as one of the contributors of the FEMA/NIST published public report on the collapse hypothesis.

Also, performed an investigation of the collapse of WTC7. The investigation included a 3D FEM using ANSYS with NL floor elements, incorporating geometric and materials non-linearity to simulate the collapse of the structure under fire loading. The investigation was geared towards finding if any lack of redundancy in the structural system caused the collapse. Written a report about the cause of collapse which was PEER reviewed and published to the public.

PROJECT: Investigation of Post-Tensioning Slab Systems for Excessive Sagging and Cracking – San Francisco, CA and Las Vegas, NV

Investigation related to post-tensioned slab systems; two-way P/T slab cracking in multiple Las Vegas high rise buildings (e.g., Juhl and Turnberry Place). Conducted on site real full load testing for floor loads with vibrating wire gage monitoring to verify engineering design and detailing.