2013 Session: 601

• Field Investigation of Pile Setup in Mixed Soil
  Abstract: An instrumented test pile was installed at the Bayou Zourie bridge reconstruction site as part of Louisiana Department of Transportation and Development (LADOTD) research initiative to study set-up phenomenon of piles driven in Louisiana soils. Pile instrumentation included pressure cells to measure the total pressure at the pile face, piezometers to monitor the excess pore water pressure at the pile face, and “sister bar” strain gauges to measure the strain distribution along the pile. Additional instrumentations consisted of multi-level piezometers installed within soils at different locations/depths from the pile and accelerometers attached to the piles during dynamic testing. A total of two static load tests and four dynamic load tests were conducted on the test pile. During the static load tests, the strains within the pile were measured by the strain gauges, which were used to calculate the distribution of load transfer along the pile. Both static and dynamic load tests demonstrated the increase in pile capacity (set-up) with time. Results of dynamic load tests confirmed that the pile set-up occurs at a lograrithmic rate after the end of driving and is mainly attributed to the increase in side resistance. Good correlation was observed in this study between the pile set-up and the percentage of dissipated excess pore water pressure with time. The measured excess pore water pressure suggested that a 2B (B: pile width) wide remolded zone was formed around the pile during driving. Results indicated that the changes in side resistance are directly related to the changes in the horizontal effective stress acting on the pile face.
  Authors: Chen, Qiming; Haque, Md Nafiul; Abu-Farsakh, Murad Yusuf
  Authors: Chen, Qiming; Haque, Md Nafiul; Abu-Farsakh, Murad Yusuf
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-1696
• Using Fines Content and Uncorrected Standard Penetration Test Blow Counts of Soils to Predict High Pile Rebound
  Abstract: High displacement piles have rebounded significantly while undergoing very small permanent-set per hammer blow in certain soils. This phenomenon, called High Pile Rebound (HPR) has occurred in areas of North America with numerous sites identified by the Florida Department of Transportation (FDOT). HPR was identified at six sites in Florida, during driving of square precast, prestressed concrete piles into saturated, fine silty to clayey sand and sandy clay soils. Pile Driving Analyzer (PDA) deflection versus time data, was used to develop strong correlations between fines content, uncorrected standard penetration test (SPT) blow counts (N_SPT), pile displacements and rebound. The correlations developed in this study allow the geotechnical engineer to reliably predict if HPR will occur at a proposed site where high displacement piles are planned to be driven using a single-acting diesel hammer. A design equation and a nomograph relating pile rebound to N_SPT and fines content was developed. The correlations showed that permanent-set and rebound were a direct function of N_(SPT )and fines content of the soil at pile tip. The design equation and nomograph provide a methodology that allows for the prediction of HPR during the design phase.
  Authors: Cosentino, Paul J.; Kalajian, Edward; Jarushi, Fauzi
  Authors: Cosentino, Paul J.; Kalajian, Edward; Jarushi, Fauzi
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-2880
• Dynamic Response of Freshly Placed Full-Scale Concrete Drilled Shaft due to Vibration from Adjacent Shaft Installation
  Abstract: A number of studies have been conducted in an effort to understand wave attenuation and sound response during installation of deep foundations. This research stems from the need to better understand the effect of vibration on freshly placed and maturing concrete within 24-hours after initial placement. Construction activities create vibratory inducing forces, which unaccounted for or unmitigated, have detrimental effects to existing and newly placed structures. The differences between common construction vibrations, and those produced during deep foundation construction, are the amplitudes and durations. The study focuses on effects during the installation of deep foundations through vibratory methods and the age effect of the vibrations on freshly placed concrete. The installation followed the Florida Department of Transportation (FDOT) guidelines. During the drilled shaft casing installation, vibration is transmitted from the source of installation to the surrounding soil causing ground motion affecting the adjacent structures. The intensity of the ground motion and the severity of the induced vibration depend on factors, such as soil type, form of amplitude-time history of the vibration, polarity of certain type of waves, and configuration of the adjacent structures. The field investigation monitored peak particle velocities during installation and their effect on freshly placed concrete. The principal findings from the field study were: (1) vibrations with peak particle velocities of up to 2.5 in/sec do not cause damage to the fresh concrete at distances of two times the shaft diameter and beyond, and (2) in general, a spacing of three times the shaft diameter is a safe specification for ensuring that shaft vibration does not damage the concrete.
  Authors: Reddy, Dronnadula V; Gonzalez-Mier, Carlos; Sobhan, Khaled
  Authors: Reddy, Dronnadula V; Gonzalez-Mier, Carlos; Sobhan, Khaled
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-4722
• Insertion Rate Model for Pile Installation by Jetting in Sand
  Abstract: The use of jetting is an approach that is used to aid the installation of the piles especially in areas encompassing hard but relatively shallow subsurface soil layers. Employing pile jetting for a part of the depth installation minimizes pile exposure to excess stresses as well as energy savings and noise reduction. There is however a dearth of information in literature regarding the appropriate selection of jetting parameters, including flow rate and jet velocity that are appropriate for the strength of a given soil profile. Work in this study presents a model for estimating pile jetting parameters based on results from laboratory and field testing. The model is based on idealization of the applied shear stresses of the jet and the shear strength of the soil. The model is applied to 19 field installations where the jetted depth ranged from 10-34 ft (3.05 m to 10.36 m). The field data yield ratios of jet flow rate to rate of pile volume insertion with time (Qw/Qp) of 6 to 17 with lower ratios associated with higher velocities. The proposed model yielded an estimation of Qw/Qp that was +/- 16% of the measured values.
  Authors: Gabr, Mohammed A.; Borden, Roy H.; Denton, Levi; Smith, Alex
  Authors: Gabr, Mohammed A.; Borden, Roy H.; Denton, Levi; Smith, Alex
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-1231
  Practice-Ready: Yes
• Identifying High Pile Rebound Soils Using Cone Penetrometer Pore Water Pressure Measurements: Case Studies in Central Florida
  Abstract: At certain depths during large diameter displacement pile driving, rebound well over 0.25 inch was experienced and followed by a small or zero set during each hammer blow. High pile rebound (HPR) soils may stop the pile driving and results in a limited pile capacity. The overburden depth at which HPR occurred is typically greater than 50 ft. In some cases, rebound leads to pile damage, delaying the construction project, and the requiring foundations redesign. HPR was evaluated at six Central Florida sites, during driving of square precast, prestressed concrete piles driven into saturated, fine silty to clayey sands and sandy clays. Pile Driving Analyzer (PDA) deflection versus time data, recorded during installation, was used to develop correlations between cone penetrometer (CPT) pore-water pressures, pile displacements and rebound. Fifteen CPT tests with pore-water pressure measurements (CPTu) were evaluated and comparisons were made to HPR from eleven piles at the six sites. At four sites where piles experienced excessive HPR with no or minimal set, the CPTu pore-water pressure yielded very high positive values of more than 20 tsf. However, at the site where the pile rebounded, followed by an acceptable permanent set, the measured CPTu pore-water pressure ranged between 5 and 20 tsf. The CPTu pore-water pressure exhibited values of less than 5 tsf at the site where no rebound was noticed. In summary, direct correlations between CPTu pore-water pressure and rebound were produced, which could be used to identify soils that produce HPR.
  Authors: Cosentino, Paul J.; Kalajian, Edward; Jarushi, Fauzi; Krajcik, Ryan
  Authors: Cosentino, Paul J.; Kalajian, Edward; Jarushi, Fauzi; Krajcik, Ryan
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-2871
  Practice-Ready: Yes
• Identifying High Pile Rebound Soils Using Cone Penetrometer Pore Water Pressure Measurements: Case Studies in Central Florida
  Authors: Cosentino, Paul
  Authors: Cosentino, Paul
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-2871
• Identifying High Pile Rebound Soils Using Cone Penetrometer Pore Water Pressure Measurements: Case Studies in Central Florida
  Authors: Jarushi, Fauzi
  Authors: Jarushi, Fauzi
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-2871
• Using Fines Content and Uncorrected Standard Penetration Test Blow Counts of Soils to Predict High Pile Rebound
  Authors: Cosentino, Paul
  Authors: Cosentino, Paul
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-2880
• Using Fines Content and Uncorrected Standard Penetration Test Blow Counts of Soils to Predict High Pile Rebound
  Authors: Jarushi, Fauzi
  Authors: Jarushi, Fauzi
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Bridges and Other Structures; Construction; Geotechnology
  Session: 601
  Paper Number: 13-2880