Lew Sterrett Justice Center
Rone completed a geotechnical study for a new four-story addition to the medium security Lew Sterrett Justice Center at the northwest corner of Industrial Boulevard and Commerce Street in Dallas, Texas. Rones client for the project was Dallas County. Rone was under contract to provide services for Dallas County during the timeframe of the project, and is still under contract with Dallas County for projects within a designated quadrant of the county.
As was the case at the time of the Lew Sterrett project, the Lew Sterrett facility is not, and was not in the quadrant to which Rone had been designated. However, due to the complexity of the project, Dallas County officials were compelled to request Rone conduct the geotechnical investigation as they did not believe that the firm which held the contract for that quadrant was capable of developing geotechnical recommendations given the difficulties known to exist in the subsurface soils.
The difficulties included the fact that the site is in the Trinity River alluvial deposit zone and that these deposits were known to consist of uncontrolled fills, including waste materials such as automotive tires, car parts, metal and other heavy debris.These conditions had been discovered during previous construction activities on the site and were anticipated at the proposed addition. Rone completed eight soil borings on site to depths of 130 to 140 feet below existing grade. The borings were successfully completed through conditions of debris, groundwater and flowing sands. Shale was encountered 100 to 110 feet below grade and was successfully sampled utilizing rock coring procedures.
Two alternatives were provided for foundation recommendations. These recommendations included straight sided, cast-in-place, cased drilled shafts, or auger cast-in-place piles (ACIP). The advantage of the ACIP system is that the installation procedure can easily navigate the variable fill soil conditions and eliminate the difficulties associated with installation and removal of temporary steel casing associated with traditional drilled shaft construction.
As a result of the thorough geotechnical study and detailed soil and foundation recommendations, the Lew Sterrett Justice Center addition was successfully completed without encountering unanticipated conditions or challenges during the foundation installation process.
George Allen Courts Building Addition
Rone completed a geotechnical study in downtown Dallas, Texas for a proposed addition to the George Allen Courts Building. The addition would have one level below grade and eight levels above grade and would structural connect to the existing eight-story tower. At the time of the investigation, below grade parking was present in the area of the proposed building footprint.
In addition, an extensive underground utility network ran along the sidewalks and streets adjoining the site. Consequently, it was necessary to drill the borings from within the parking structure to depths up to 40 feet in the underlying limestone. In order to drill within the garage, it was necessary to breakdown the drilling mast on the rig and work in a confined height condition presenting a challenging, yet achievable operation.
The project required extensive coordination with the occupants of the George Allen Courts building such that drilling operations did not substantially impact access to the garage by employees and visitors. The design team, which included Vidaud Associates, worked in harmony to coordinate and complete the field activities with minimal interruption to the daily routine. Weekend and evening drilling activities were among the adjustments incorporated to accommodate the client.
Limestone bearing materials were encountered within 8 to 14 feet of the drilling surface and recommendations for foundations consisted of straight sided drilled shafts bearing in gray limestone. Due to the below grade requirements of the proposed construction, detailed construction shoring recommendations were prepared and provided as well.