Setup Prediction of Piles Driven into Louisiana Soft Clays

Wang, X.; Verma, Neha; Tsai, Ching; Zhang, Zhongjie

doi:10.1061/41095(365)159

Cited by 7 publications

(7 citation statements)

References 2 publications

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“…It predicted pile resistance gain by assuming that the pile resistance increases with logarithmic time. Svinkin et al (1994), Axelsson (1998), Camp and Parmar (1999), Bullock et al (2005a, b), Yang and Liang (2006), and Wang et al (2011) presented reasonable predictions following similar equations for clayey and sandy soils. In addition, other empirical methods were also proposed and employed to estimate the pile resistance growth.…”

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confidence: 62%

“…Friction piles take a significant portion of their loads via the skin friction developed along the surface of the piles. In the LA-1 relocation project, tip resistances of the piles were mostly only about 10-15 % of the shaft resistances (Wang et al 2011). Based on the existing pile testing results, the tip resistance and shaft resistance distributions achieved from the CAPWAP analyses were consistent with those obtained from the final static load tests in most cases.…”

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confidence: 66%

“…The ultimate axial resistance of a driven pile can be much greater than the initial resistance obtained immediately after installation, as reported by case histories in literature and local field testing data in Louisiana (Titi and Wathugala 1999;Soil Testing Engineers 2004). For instance, shaft resistances of some PPC driven piles at the LA-1 relocation project site increased by 30-100 % during the first week after the end of driving, and resistances of some piles had significant growth even after 3-7 months (Wang et al 2011). Khan and Decapite (2011) found that set-up occurred commonly in driven steel piles in Ohio soils, and some degree of set-up was observed in 91 % cases they collected.…”

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confidence: 95%

“…Svinkin (1996) presented a method to estimate the upper and lower bounds of pile resistances. Brief summaries of those empirical methods could be found in Svinkin et al (1994), Tan et al (2004), Yang and Liang (2007), and Wang et al (2011), etc. Tan et al (2004 recommended and elaborated the empirical hyperbolic equation proposed by Bogard and Matlock (1990) based on the collected data from different field tests.…”

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confidence: 98%

“…Shear strength and frictional angle of soils increased more dramatically with greater over-consolidation ratio OCR. The friction angle increase due to aging between soil and concrete pile wall was mathematically formulated for the first time by Steward and Wang (2011) and Steward (2011). The deterministic model, requiring the time-dependent effective friction angle between pile wall and remolded clayey soils, could be employed to calculate pile resistance that increased with time by accounting for soil properties of multisoil layers the pile was driven through and the effect of groundwater table.…”

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confidence: 99%

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Estimating Pile Set-up Using 24-h Restrike Resistance and Computed Static Capacity for PPC Piles Driven in Soft Lousiana Coastal Deposits

2015

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In this paper, the CPT-based predicted ultimate pile resistances (R p ) were compared with the measured pile resistances (R m ) at different elapsed time for the piles driven into saturated soft clays where piles displayed significant set-up effect. The measured pile resistances were based on 115 restrike records collected from 95 production piles, and 74 records of 9 tested piles. The predicted ultimate pile resistances were calculated from the LCPC, the Schmertmann, and the de Ruiter-Beringen methods, respectively. With the significant pile set-up effect taken into account, the relationship between measured resistances and predicted capacities at different times after pile installation were investigated. The ratios of the measured pile resistances to the predicted capacities scattered in a large spectrum. The ratios fluctuated and stayed within a range of 0.6-1.6 for different CPT methods since end of initial driving until more than 2 months after pile installation. Plots of the ratios versus the predicted pile capacities using different CPT methods have revealed that the ratio (R m /R p ) presented a strong dependence on the predicted capacities. Great research efforts have been devoted to the analyses of the ratios of the 24-h measured resistance to the predicted capacity based on different CPT methods, in an attempt to find a feasible empirical correlation. It is found that a simple linear relationship exists between the quad root of the ratio and the predicted capacity. The developed empirical equations will give pile foundation engineers an insight into the ultimate resistances of driven piles demonstrating significant pile set-up effects. Pile set-up makes pile resistances grow with time, and it might be one of the reasons that cause the frequently reported large discrepancy between calculated static capacity and measured resistance at a certain time after pile installation.

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confidence: 62%

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confidence: 66%

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confidence: 95%

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confidence: 98%

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confidence: 99%

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Estimating Pile Set-up Using 24-h Restrike Resistance and Computed Static Capacity for PPC Piles Driven in Soft Lousiana Coastal Deposits

2015

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Variations in the Capacity of Driven Energy Piles in Clay

Farid,

Zimmerman

2023

Lecture Notes in Civil Engineering

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Time-Dependent Capacity Increase of Piles Driven in the Puget Sound Lowlands

Reddy

Stuedlein

2014

From Soil Behavior Fundamentals to Innovations in Geotechnical Engineering

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Piles driven in the Puget Sound Lowlands frequently exhibit a high magnitude of soil setup or gain in capacity over time. In fact, the energy associated with production pile driving hammers is often insufficient to fully mobilize pile toe bearing resistance during dynamic restrike testing. Due to the potential for significant increases in capacity, practitioners often must consider the uncertain trade-off between the potential for setup and time-to-restrike. This study presents the results of 76 pile case histories from the Puget Sound Lowlands that were dynamically monitored during end-of-drive (EOD) and begin-of-restrike (BOR). The setup time (i.e. time between EOD and BOR) ranged from 5.5 to 312.5 hours. Signal matching using CAse Pile Wave Analysis Program (CAPWAP) indicated that the majority of the piles experienced significant increases in shaft resistance. In order to assess setup, piles were grouped into three categories: closed-end steel pipe piles, open-end steel pipe piles, and solid concrete piles. The accuracy and uncertainty of the well-known Skov and Denver (1988) setup prediction model was evaluated using the mean bias, defined as the ratio of measured and predicted shaft resistance, and the coefficient of variation (COV), defined as the ratio of the standard deviation of the point biases to the mean bias. The Skov and Denver model exhibited considerable uncertainty (COV = 45 to 59 percent) when evaluated using the local database. Recalibration efforts made using a hyperbolic function and least squares regression resulted in a reduction of the COV to 29 to 32 percent. Based on considerable scatter in the setup ratio (i.e. ratio of BOR to EOD shaft resistance), it was determined that the behavior of setup over time could not be adequately captured by considering total shaft resistance. Therefore, setup due to the overall increase in shaft resistance between EOD and BOR was characterized in an initial effort to provide guidance for incorporating setup into pile design. Closed-end concrete piles exhibited the largest average setup ratio (3.92), followed by closed-end steel piles (2.37) and open-ended steel piles (2.26).

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Setup Prediction of Piles Driven into Louisiana Soft Clays

Cited by 7 publications

References 2 publications

Estimating Pile Set-up Using 24-h Restrike Resistance and Computed Static Capacity for PPC Piles Driven in Soft Lousiana Coastal Deposits

Estimating Pile Set-up Using 24-h Restrike Resistance and Computed Static Capacity for PPC Piles Driven in Soft Lousiana Coastal Deposits

Variations in the Capacity of Driven Energy Piles in Clay

Time-Dependent Capacity Increase of Piles Driven in the Puget Sound Lowlands

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