Forensic Evaluation of Existing Structures

Twining’s roster includes leading experts on a wide variety of construction materials, from structural steel to concrete and masonry. We utilize their knowledge and experience not only during the design and construction of new structures, but also by providing in-depth evaluation of existing structures. Their expertise is complimented by our network of fully accredited laboratories that provide reliable testing overseen by registered engineers.

Field Services

  • Location and documentation of reinforcement
    • Ground penetrating radar (GPR)
    • Pachometer
    • Radiography
  • Concrete coring
  • Extraction of reinforcement samples
  • Extraction of structural steel coupons
  • Extraction of masonry prisms
  • Visual inspection and UT/NDT testing of structural steel connections
  • Documentation of wood framed structures
  • Lumber grading services
  • Documentation of structural elements
    • Photographs
    • Video
    • AutoCAD drawings
  • Half cell potential testing
  • V-meter testing
  • In place shear testing of unreinforced masonry
  • Full scale load testing
  • In place compressive strength testing of masonry walls (Flatjacking)
  • Anchor pullout and shear testing

Twining’s structural evaluation division specializes in providing turnkey evaluations with no disruption to the structure’s occupants, even in the most critical of environments. For example, we’ve successfully extracted masonry wall prisms in a functioning Intensive Care Unit (ICU) by creating a fully encapsulated negative pressure work area. We’ve also worked in correctional facilities, libraries, judge’s chambers, mayor’s offices and other sensitive environments.

Laboratory Services

  • Testing of concrete cores
    • Compressive strength
    • Unit weight
    • Modulus of elasticity
    • Modulus of rupture
    • Splitting tensile
    • Chloride profile
    • pH profile
    • Petrographic analysis
  • Testing of masonry prisms
    • Compressive strength
    • Unit weight
    • Modulus of elasticity
  • Testing of reinforcement
    • Yield and tensile
    • Percent elongation
    • Modulus of elasticity
    • Carbon equivalent
    • Chemical composition

These and other testing services are carried out in our network of laboratories accredited by NIST, DSA, CCRL, AMRL/AASHTO, the Army Corps of Engineers, City of Los Angeles and others.

Consulting Services

Twining’s experts provide consulting services related to the evaluation of existing structures and on the requirements of FEMA, OSHPD and SB 1953.