A Self-Learning Manual - Institution of Engineers Mauritius

A Self-Learning Manual
Mastering Different Fields of Civil Engineering Works (VC-Q&A Method) Vincent T. H. CHU
(i) Quality of concrete (e.g. honeycombing)
(ii) Location and type of damages
(iii) Estimation of pile length
However, it is mainly used to check the integrity of piles only and it may be
used to deduce the pile capacity.
5. What is the difference between Case Method and CAPWAP
Analysis? (PDA1)
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.
6. What are the limitations of plate load test?
Plate load test is carried out to check the bearing capacity of foundation
soils. The limitations of plate load test are:
(i) It has limited depth of influence. It could only give the bearing
capacity of soils with depth up to two times the diameter of plate.
(ii) It may not provide information on the potential for long term
consolidation of foundation soils.
(iii) There is scale effect as the size of test plate is smaller than actual
foundation.
(iv) To gain access to test position, excavation is carried out which
causes significant ground disturbance. The change in ground stress
leads to the change of soil properties which the test is planned to
investigate.
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