A Closer Look at Prevailing Civil Engineering Practice - European ...

A Closer Look at Prevailing Civil Engineering Practice, What, Why and How
Vincent T. H. CHU
over time ( ∫Fvdt ).
(iv) Determine if pile damage has occurred.
Pile integrity can be checked by inspecting the measurements for
early tension returns (caused by pile damage) before the reflection
from the pile toe. The lack of such reflections assures a pile with no
defects.
There is a growing trend of using PDA test to check driven pile capacity
instead of traditional static load test which is more expensive and
time-consuming. Some engineers may have reservation on the use of
dynamic formula to evaluate driven pile capacity because of the fear of
improper selection of quake values and damping factor.
19. What is the difference between Case Method and CAPWAP
Analysis
High Strain Dynamic Testing consists of two main types, namely Dynamic
Pile Monitoring and Dynamic Load Testing. Dynamic Pile Monitoring
involves the use of PDA to perform real-time evaluation of Case Method
pile capacity, hammer energy transfer, driving stresses and pile integrity for
every blow count. On the other hand, Dynamic Load Testing is another
technique that is evolved from wave equation analysis. CAPWAP Analysis
makes use of field measurements obtained by PDA and wave-equation
type analytical method to predict pile performance such as static load
capacity, pile-soil load transfer characteristics, soil resistance distribution,
soil damping and quake values. CAPWAP Analysis is carried out on the
PDA data after the test is complete.
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