AirTricity
Sterling City, Texas

Project Description:

• The challenges imposed upon the project consisted of a variable subsurface condition predominately of soft to moderately hard fossiliferous limestone bedrock, low availability of water for core drilling and harsh environmental conditions. Due to the lack of water for wet rotary drilling, air rotary was chosen for this project. This type of drilling technique usually produces poor core run recoveries and low rock quality designation, which in-turn produces conservative engineering recommendations for foundation designs.
• With the cost of the foundations approximately $4,500.00 per each foot of excavation, the client expressed its desire to economize the embedment depths. In an effort to reduce the cost of the foundations, Kleinfelder performed vertical seismic profiling to determine the subgrade shear modulus and appropriate rotational stiffness values as an aid in determining the required embedment depths for the foundations. The outcome of the analyses indicated that most foundations would only require five feet of excavation, therefore, saving the client in excessive foundation costs.