MUTHANNA JOURNAL OF ENGINEERING AND TECHNOLOGY (MJET)
ASSESSMENT OF NATURAL RADIOACTIVITY LEVELS AND RADIATION HAZARDS FOR BUILDING MATERIALS USED IN SOME SELECTED PROVINCES IN IRAQ
Research Article:
Raid R. Al-Omari
Civil Engineering Department, Al-Nahrain University, Baghdad, IRAQ,
Hussein Mandeel Ashour
Civil Engineering Department, Al-Muthanna University, Samawa, IRAQ
Basim Jabbar Abbas
Civil Engineering Department, Al-Muthanna University, Samawa, IRAQ
E-mail addresses: tosharaid@yahoo.com, alkhuzaie@yahoo.co.uk and basm.jabar@yahoo.com
ABSTRACT
This paper investigates the effect of soil-pile cap interaction on the dynamic behavior of the
soil-pile system under vibrations. Vertical vibration tests were conducted using experimental
models of pile footings embedded in a finite dry sand layer. The pile footings consist of two
groups of circular piles with spacing/diameter (S/d) ratio equals to 5; the length/diameter
(L/d) ratio for first group was 13.3 and for the second was 20. Each group includes models
with different number of piles. A physical model made of steel box of dimensions of 700 ×
700 mm and 800 mm in height was used for accommodation the test model. In order to
study the effect of cap interaction, the first tests were conducted where a gap was left
between the caps and sand surface as reference, and the second tests all caps in contact with
sand surface. The maximum displacement amplitudes and the corresponding resonant
frequencies of the experimental system were measured using vibration meter and
accelometer fixed on the top of the pile cap. The results of both groups indicated that the pile
cap interaction significantly increases the vertical amplitudes and increases slightly the
resonant frequencies in different proportions