Foundation Movements and Welding Defects in Precast Parking Garage

Carrasquillo Associates (CA) was retained in 2013 to investigate alleged construction defects in a precast parking garage supported by drilled piers near Austin, TX. As part of CA’s investigation, welds were inspected at broken precast connections, relative elevation surveys were performed near distressed areas, cracking was mapped throughout the structure, and a comprehensive finite element method (FEM) model was created for the garage. The FEM model allowed CA to analyze the effect of the measured support settlements to evaluate the cause(s) of the observed distress. Using this information, CA also evaluated the repair scheme being implemented to address the distressed areas throughout the structure.

Causes and Ramifications of Distress in Post-Tensioned Multimodal Transit Facility

Carrasquillo Associates (CA) was retained in 2016 to investigate distress in a multimodal transportation hub located in the northeast United States.  The cast-in-place structure consisted of a slab on ground and two elevated slabs supported by a concrete frame. The elevated slabs as well as the concrete beams and girders were post-tensioned (PT). CA investigated concerns related to cracking in the concrete slab and frame, reinforcement cover, and concrete durability. As part of the investigation, CA made a site visit to the structure and also reviewed numerous documents including, among others, design drawings, specifications, photographs, shop drawings, expert reports, testing reports, and communications between parties. CA’s investigation helped to identify the causes and ramifications of the observed distress which allowed the parties to come to an agreement regarding the damages.

Crane Rail Wear and Misalignment

Carrasquillo Associates (CA) was retained in 2014 to investigate unusual wear on crane rails in a steel processing plant in Pennsylvania. CA conducted an on-site investigation to measure the severity of the crane rail wear and to determine its cause. Custom crane rail measuring devices were fabricated at a machine shop in Austin, TX for this purpose. In addition, CA reviewed numerous surveying reports to verify dimensional compliance between laser surveys, project specifications and industry standards. Life cycle estimates of the crane rails were made based on the information collected during the site visit and research conducted by the US DOT.

Forensic Investigation into Distress of Rigid Pavement

This project consisted of various segments of approximately 9.7 miles of Portland Cement Concrete Pavement (PCCP) on Road US 64/87, located in Union County near Des Moines, New Mexico. The project was divided into East Bound Lane and West Bound Lane sections each consisting of two traffic lanes. CA was retained to identify the possible cause(s) and/or contributing factor(s) of the distress in the PCCP, as well as the repairs made during and after construction. The investigation included on site evaluation, photographic documentation, analysis of technical documents, among others. CA was able to identify segments of most distress associated with concrete placement and location, and the cause(s) of the distress associated with the PCCP.

Alkali-Silica Reaction (ASR) in Pier Structure

Carrasquillo Associates (CA) was retained in 2012 to investigate concerns about the structural integrity and long term performance of a pier structure in Honduras and to determine the deterioration mechanisms affecting the durability, the structural safety and useful life of the structure. The investigation into the structure included visual inspection, crack monitoring, concrete sampling, petrographic examination, chloride testing, structural analysis, and half-cell testing among other items. Based on the testing performed, the internal concrete expansion damage mechanism was identified and the remaining service life of the structural performance of the structure was assessed. Further, several alternatives for restoring the service life and the facility were evaluated. This allowed the client to better understand the cause of the distress that was being observed and what needed to be done to allow the structure to continue to operate safely moving forward.

Forensic Engineering Investigation & Analysis of Bridge Overlay Failure

The Pulaski Skyway Bridge Project consisted of a steel truss bridge supporting a concrete bridge deck with repairs where the top 1.5 inches of concrete bridge deck was replaced with a latex modified concrete topping along the entire length. Shortly after, the repairs began to exhibit premature failure in the form of reflective cracking around the perimeter of the repaired area, then debonding, followed by cracking of the patch repair material causing eventual potholes in the bridge deck. CA’s investigation involved, among others, review of daily log reports, expert reports, and other relevant documents, and a site visit during which a visual condition survey was performed to determine the cause(s) of the observed premature patch repair failures in the bridge deck.

Tennis Court Complex Forensic Engineering Investigation

CA was retained to perform a structural investigation and determine the cause(s) of the distress in two tennis court facilities located at a junior high school and high school in South Texas. To accommodate construction on expansive soil conditions, the structural system of the tennis courts was comprised of precast concrete hollow core planks (HCP) with a 3 inch concrete topping slab supported by cast-in-place reinforced concrete piers. Shortly after construction the owner noticed distress in the form of cracking and spalling along joints in the playing surface of the tennis courts. It was determined that the cracking was reflective cracking propagating from the longitudinal and transverse joints between HCPs which also resulted in localized spalling of the topping slab. CA’s investigation into the problem consisted of, among others, review and evaluation of construction related documents, review of third party repair options, review of expert reports, review of plans and drawings, detailed condition survey and elevation surveys, exploratory coring to assess the details of the jointing between HPCs, structural analysis of the tennis court system, design of a repair alternative, as well as several site visits to the structures. Through the forensic engineering investigation, CA was able to determine the cause(s) of the distress and provide the client appropriate remediation procedures.

Foundation Crack Repair of High School in Texas

CA was retained to determine if the alleged movement of the reinforced concrete slab-on-grade foundation at a high school was the result of construction related activities and to develop recommendations for restoring the facility. Shortly after the school’s completion, the owner reported deficiencies including, but not limited to, movement of the slab-on-grade foundation which caused distress consisting of cracking and/or separation of drywall panels, out-of-plumb doorways, and out of level floors. CA’s investigation included the review and evaluation of construction related documents, multiple site visits including a detailed condition survey and relative elevation surveys of the school. Through the investigation, CA was able to determine the cause(s) of movement and develop a mitigation procedure to minimize any future movement and restore functionality of the facility.

Structural Engineer Expert Witness: Sports Car Speedway

In January of 2012, a barrier wall at a race track near Houston, Texas was struck by a vehicle resulting in injuries to a spectator. Carrasquillo Associates (CA) conducted a forensic investigation into the structural integrity of the barrier wall. CA’s investigation and litigation support included review of depositions, photographs, drawings, expert reports and industry standards for vehicle barrier design. In addition, CA performed a structural analysis on the as-built barrier wall and after a site investigation to identify distress and the as-built condition of the wall. CA’s investigation culminated in an expert report where CA was able to determine the injuries to the spectator were attributable to the structural deficiencies in the barrier wall and poor safety practices at the facility. The case was settled in favor of CA’s client.

Warehouse Slab-on-Grade Distress Investigation

A 160,000 square foot warehouse located in Austin, TX was exhibiting distress of the finished concrete floor in the form of aggregate exposure, distress, surface wear, and joint deterioration of both control joints and construction joints in the cast-in-place slab-on-grade. In addition, several areas were identified as containing cold joints and poor quality concrete within the cast-in-place slab-on-grade. CA was retained to perform a detailed condition survey to identify and determine the cause(s) of the defects within the slab and to develop concrete repair recommendations. CA’s condition survey included photographic documentation, distress mapping, non-destructive testing using ground penetrating radar, concrete core sampling, and petrographic examination. The investigation also included an assessment of the equipment and use of the facility as well as an evaluation of the specifications, plans, drawings and construction related documents. CA determined the cause of distress in the concrete and provided the client with a repair plan to prevent future distress that would have otherwise been caused by the existing defects within the slab-on-grade.  CA also aided in the litigation for this project by participating in mediation proceedings.