Our San Jacinto laboratory is accredited by AASHTO R18 for soil, aggregate, concrete and masonry, and approved by Caltrans and the California Division of State Architect (DSA). All laboratory construction materials testing is performed in accordance with ASTM or Caltrans test methods, by certified technicians. We also participate in laboratory benchmark sample reference programs administered by; Caltrans, Cement and Concrete Reference Laboratory (CCRL), and American Association of State Highway and Transportation Officials (AMRL) Materials Reference Lab. Geophysical methods used for site investigation include seismic refraction surveys and shear wave surveys. For a hard rock site, we typically use rock coring equipment to obtain samples and perform seismic refraction surveys (geophysical) to evaluate the hardness and excavation characteristics of the rock. For a loose sandy site, we often use rotary drilling rigs to obtain samples and evaluate the liquefaction and seismic settlement characteristics. CPT, backhoe, and other investigation methods may be used in conjunction with drilling and coring, depending on the specific geologic and soil characteristics.