This paper presents 53 well-documented cases of the short-term set-up of open-ended steel pipe piles driven at two fields in the North Sea. Increases in soil resistance during driving (set-up) were observed when pile driving was re-started after delays typically ranging between 24 h and 100 h. The soil encountered at the sites consisted of overconsolidated sands and clays, where the clays varie...

Free vibration of soil often occurs during earthquakes. Since the vibration caused by earthquake does not have (steady state harmonic vibration) continuity, the alluvium vibrates with its natural frequency between two natural seismic waves. This study evaluates the effect of piles on the period of free vibration of a soil layer using numerical method. In the first stage, using analytical equati...

Intraguild predation of Neoseiulus cucumeris Oudemans (Phytoseiidae) by soil-dwelling predators, Dalotia coriaria Kraatz (Staphylinidae) may limit the utility of open rearing systems in greenhouse thrips management programs. We determined the rate of D. coriaria invasion of N. cucumeris breeder material presented in piles or sachets, bran piles (without mites), and sawdust piles. We also observ...

This study gives the reliability analysis of bearing capacity of large-diameter piles under osterberg test. The limit state equation of dimensionless random variables is utilized in the reliability analysis of vertical bearing capacity of large-diameter piles based on Osterberg loading tests. And the reliability index and the resistance partial coefficient under the current specifications are c...

one of the important issues in hydraulic engineering is inspection of local scour depth around bridge pier. using piles is one of the ways for confronting local scour and erosion. in this study, the experiments were conducted in an 8m long, 0.5m deep and 0.25m wide flume. and the effectof using piles and number of them observed on the amount of scour in three different frude numbers. the shape ...

Negative skin friction occurs when concrete piles are situated in soft soils, consolidating soilmass, etc., resulting in a downward force that increases loading on shaft piles and reduces the bearing capacity of the piles. A new concept based on the shifting rate of piles, and the settlement rate of the surrounding soils has been suggested far the study of negative skin friction. Negative skin ...

Most Codes such as API and BSI recommend Morison’s equation to estimate hydrodynamic forces on offshore structures. Significant differences exist among these Codes due to using different methods of analysis and estimation of force coefficients. In this paper, data from full scale tests have been used to evaluate random waves and uniform current actions on the smooth piles. Four time and ...