Likins G.E.,Pile Dynamics Inc. |
Fellenius B.H.,Rothesay Avenue |
Holtz R.D.,University of Washington
Geotechnical Special Publication | Year: 2012
Dynamic formulas were in common use in the early part of the 1900s to estimate capacity of a driven pile, and many comparisons were then made with static loading tests. An ASCE Committee was formed in the 1930s to review and make recommendations on the proper use of dynamic formulas; after almost a decade long study, a report was issued in May 1941. The report generated considerable controversy and a remarkable 28 discussions in the Proceedings of the ASCE by several very high profile engineers. Considering the current renewed search by some agencies to find a better dynamic formula, primarily to increase the LRFD resistance factor to make designs more economical, it is prudent that we revisit this work to avoid repeating some of the same mistakes. Our review of the extensive discussion comments is presented to better define the problem, and to produce more realistic expectations of what can be achieved by a dynamic formula. The discussions also included to a lesser extent considerations of static loading test procedures and interpretations, which are also discussed in this paper. © 2012 American Society of Civil Engineers. Source
Pile Dynamics Inc. | Date: 2012-10-16
Pile Dynamics Inc. | Date: 2013-01-16
A system for monitoring the forming of a solid object having a sensor string positionable in a forming structure before the curing process and a communication line extending along a string axis between a first and second end. The string further including a plurality of sensors joined to the communication line between the ends and each sensor being mounted at a set position on the line. Each sensor having a sensor body and a sensor housing and the sensor body including an electrical connecter to electrically join an electrical structure to the communication line at the set position. The electrical structure including a temperature sensor configured to monitor temperature near the set position and further including an electronic identification code corresponding to the set position of the sensor along the axis. The system further including a transmitting device for selectively communicating the temperature and identification code.
Pile Dynamics Inc. | Date: 2012-10-05
A pile testing system for determining the load capacity of an in place pile and the system including a transducer assembly having a top extent and a bottom extent, the transducer assembly being generally fixed relative the pile top when in use and having a side wall transverse to the pile top and extending about a transducer axis, the transducer assembly further including at least one strain transducer joined to the wall of the transducer assembly, the at least one strain transducer configured to measure the applied load, the system further including at least one accelerometer fixed relative to the associated pile, the at least one accelerometer configured to calculate the movement of the associated pile when subjected to the applied load wherein the load capacity of the associated in place pile can be calculated based on the comparison between the applied load and the movement of the pile.
Pile Dynamics Inc. | Date: 2011-06-14
A measurement device system and method of using the same for determining the depth of a pile being installed and/or the equipment used to install the pile. The device including an encoder assembly having a support attachable to a structural component of a rig wherein the support has a pivot joint coaxial with a load arm axis. The encoder assembly has a load arm rotatable about the arm axis and with a wheel near its distal end that is rotatable about a wheel axis with an encoder joined to the wheel that moves with the wheel. The encoder assembly further including a biasing assembly to urge the load arm and wheel into an engaged condition relative to the associated pile installation machine such that the wheel frictionally engages a surface of another structural component of the rig. Thus, the displacement of the first structural component relative to the second component rotates the wheel about the wheel axis and the encoder. This information can then be used to determine pile depth.