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By Vahid Tajdar

The behavior similarity between pile and cone penetration test, has guided the researchers to use the CPT results in prediction of piles bearing capacity. In this article, artificial neural networks have been used to study about relation between cone tip and sleeve friction strength obtained from cone penetration test and ultimate pile bearing capacity, obtained from static pile load test. Artificial neural networks "ANNS" is a form of artificial intelligence. ANN tries to dramatize the human nerves & brain system biology structure in self-structure. In this article, the results of relevant studies about the prediction of ultimate pile bearing capacity in especial area of soils are presented by use of back - propagation neural networks. The results of static pile load test up to failure on 63 piles with closed end and CPT test results in the place of construction these piles use in order to confirm and creation ANN model. Comparing predicted ultimate pile bearing capacity by utilizing ANN with the numbers which are predicted by 5 common traditional methods shows that using of artificial neural networks is a suitable method for predicted ultimate pile bearing capacity in identified area of texture of soil moreover it has a better operation in comparison with common traditional methods.

Jan 1, 2006

By David A. Staab

Numerical modeling was used to investigate the feasibility of using two geophysical imaging techniques, cross-borehole ground penetrating radar (XBGPR) tomography and electrical resistivity (ER) tomography, for detecting and characterizing defects in deep-mixed soil columns. XBGPR modeling was accomplished with a three-dimensional numerical forward modeling code and a two-dimensional inversion routine. Spatial variations in apparent dielectric constant (Ka) and attenuation (a) were mapped. Electrical resistivity modeling was accomplished with a three-dimensional numerical forward modeling code and a three-dimensional inversion routine. Spatial changes in electrical resistivity were then mapped. Three different types of defects were simulated, in addition to a defect-free column. The computer simulations suggest that XBGPR tomography and ER tomography might be useful, non-destructive methods for detecting and estimating the extent of defects in deep-mixed soil columns. The results show that small, isolated defects might be difficult to detect, but defects approximately equal to or larger than the sampling interval (for XBGPR) or vertical electrode spacing (for ERT) should be detectable.

Jan 1, 2004

By Thomas Trochalides

Newtown Creek Water Pollution Control Plant in Brooklyn, NY is the largest of 14 Water Pollution Control Plants in New York City. It services over 1 million people with a current processing capacity of 310 million gallons daily. Upgrades to the plant have been underway since 1998. This paper details the foundation elements installed in three separate contracts during 2009: NC-41F, NC-36G, and NC-47G. The elements are Concrete-Filled Pipe Piles, H-Piles, Steel Sheet Piling, Secant Walls, Drilled Caissons, and High Capacity Micropiles. Soils on the site consist of fill over organic silty clay and silty sand. Beneath the organic layers lie lake sand and varved silt and clay, sitting atop glacial till and rock. Due to Federal Mandates, certain plant capacity and secondary treatment requirements had to be met by specific dates. Failure to meet the requirements would have an adverse affect on the NYC areas being serviced. Further complicating the project, the existing plant operations had to be maintained throughout the entire construction phase. To accommodate the constraints of the project, new specialty equipment and several key redesigns were used to maintain construction schedules

Jan 1, 2010

By Cheng Lin

The Group Equivalent Pile (GEP) approach was proposed by researchers to analyze a laterally loaded pile group. This approach enables engineers to evaluate the behavior of a pile group in single pile analysis software, such as LPILE. A previous study showed that the calculated results using the GEP approach for piles agreed well with field test data. To evaluate the accuracy of the GEP method for analyzing laterally loaded shafts, two case studies with different shaft diameters were performed in this study. The comparisons showed that the calculated results using the GEP method and considering the contribution of the shaft cap if embedded generally agreed with the measured from the full-scale tests.

Jan 1, 2009

By Vasileios A. Drosos

The response of pile foundations to lateral loads is an important factor for the successful performance of several critical structures. A new numerical code for the analysis of single piles under lateral load is outlined. The code can simulate (through appropriately chosen parameter values) not only the non-linear behavior of soil, but also the inelastic structural response of the pile itself under lateral load. Emphasis is given on the calibration of model parameters and the verification of the code. For the calibration of the parameters, data is used (a) from the well documented in the literature p-y curves, and (b) from experiments conducted either in full scale or in the centrifuge. Results are compared to those of well known published codes for inelastic analysis of single piles under lateral load.

Jan 1, 2006

By A. Verghese Chummar

The paper presents a field study where the effect of negative drag caused the failure of a pile foundation system. Utilising the field observations the probable negative drag that acted on the piles is worked which gives an insight into the effect of negative drag on deep foundations.

Jan 1, 1996

Abouleid,A.F.327 Ajdic, I.451 Albert, L.F. 221,307 Alem, A. 525 Asama, T. 431 Avgherinos, P. J. 373 Baker Jr, C.N. 331 Balossi Restelli, A. 171 Beckwith,G.H.33 Bellini, A. 469 Bermingham, P. 481 Bertero,M. 171,535 Beyer, M. 503 Bottiau, M.41 Botto, G. 205 Bruskeland, O. 337 Budhu, M. 349 Bullivant, R.A. 181 Bustamante, M.G. 185, 475, 535

Jan 1, 1994

By Eric C. Halpin

"1. Introduction and Backgrounda. In its fundamental form, risk is simply the likelihood of an adverse impact. Expanding on this theme, the Corps of Engineers has broadly defined risk associated with infrastructure as a factor of three distinct elements: a probabilistic assessment of a hazard such as a flood or earthquake; a probabilistic assessment of how the infrastructure performs in the face of this hazard; and a measure of the likely consequences – loss of life, economic damage, environmental impacts – associated with the resulting inundation scenarios.b. The lessons and observations described herein relate to the Corps of Engineers experiences in implementing risk concepts for infrastructure management during the period 2005 through 2013. The Corps of Engineers is a large, decentrally operated and centrally led federal agency that plans, designs, constructs, operates, maintains, and/or manages a portfolio of over 3,000 built dam and levee systems within the United States. The infrastructure in this portfolio is 55 years old on average, and although much of the structures provide for flood risk management benefits, many of the dams deliver multi-purpose benefits. Scale matters – where scale and uncertainty are large, risk concepts provide great opportunity and arrangement for application.c. The amount of organizational change that is demanded for the implementation of risk concepts is considerable and should not be under estimated, but need not be feared if the path others have taken is considered. This paper is, in many ways, an opportunity to step back from the last seven years of implementing risk informed management, check our own azimuth and maturation, and share the purpose and energy behind our own continuing actions. Hopefully, this azimuth check is also beneficial to those that are either considering the use of risk or are in the process of implementing risk concepts.d. Success at managing the massive change related to incorporation of risk concepts will directly affect success of the infrastructure program. The three key organizational elements to consider –human systems such as governance and competencies; policies that outline the who, when, and why of decisions and management; and the processes and technology that outline how work is to be performed - are changed fundamentally. From senior leaders to project team members and all of the people in between, there is a need to discuss, confront, and vet the change and the role people and organizations have in the process. For the Corps of Engineers, with a history of over two centuries, deeply embedded beliefs about infrastructure aren’t transformed over night - the change process is decadal in scope. Given our self imposed “project execution” mantra and corporate objective, risk seemed threatening at first to the cost and schedule of delivering infrastructure projects. In reality, risk concepts have been responsible for savings and cost avoidance of nearly $6 billion over the last three years alone while at the same time justifying increased investment by several fold for the highest risk needs."

Jan 1, 2014

By Patrick J. Hannigan, Alex Ryberg, Rozbeh B. Moghaddam

Driven piles are widely used for foundation support. In the vast majority of cases, an increase in pile capacity occurs with time which is referred to as “set-up.” However, in a very limited number of cases, a decrease in capacity with time can occur. This phenomenon is referred to as “relaxation.” This paper will provide a brief review of the relaxation phenomenon, as well as pile driving information and dynamic test data on cases where relaxation has occurred. The pile types in the presented relaxation cases include H-piles, open-end and closed-end pipe piles, prestressed concrete piles, and prestressed concrete piles with H-pile stingers. The soil conditions where relaxation occurred includes dense to very dense fine sands, heavily over consolidated clays, and weak laminated rocks. Relaxation information from 36 piles at 26 sites is assessed. The collected data will assist foundation designers by identifying the subsurface conditions where relaxation has occurred, as well as by documenting the corresponding relaxation magnitude. One method of addressing relaxation when it is encountered is to drive the foundation piles to a greater end of initial driving capacity than required long-term. Hence, the identification and quantification of the relaxation magnitude will be beneficial to foundation designers installing similar pile types in similar subsurface conditions. The paper will also present pertinent observations and recommendations on mitigating relaxation when encountered. INTRODUCTION One of the earliest observations of a decrease in redriving resistance following initial driving was reported by Miller (1937). He reported that piles driven into a saturated, coarse grained soil could lose 40 to 50% of their resistance when redriven 24 hours after initial driving. Yang (1956) similarly reported that after a break in driving, a decrease in driving resistance could be encountered for piles driven in dense fine sand, inorganic silt, or stiff fissured clay. Parsons (1966) in his paper that described piling difficulties in the New York City metropolitan area termed this phenomenon “relaxation”. In this time period, pile capacity was most often evaluated from a pile driving formula frequently checked by a static load test. Hence, the true magnitude of the capacity decrease on a given pile was often poorly quantified. Furthermore, dynamic measurements that could determine what influence driving system performance variation had on the observed redriving resistance were not yet readily available.

Jan 1, 2019

By Richard J. Hartman

This presentation identifies some of the more common problems associated with cofferdam construction. After the various problems are identified, they are briefly explained and possible solutions and preventive measures are noted. Photographic slides used during the seminar illustrate the conditions. This discussion is limited to cofferdams which are braced structures excavated inside to allow access for construction. The common procedure is to drive sheet piling and then alternatively install bracing and excavate. They can be located either on land or in water. Loads are applied by soil, water, surcharge pres-sure, eccentricities, and impact loads. The loads are resisted by the sheet piling, the bracing, and the soil below the bottom of the excavation; each of these three components must be capable of resisting the applied loads.

Jan 1, 1987

By Jeongbok Seo

The Dulles Corridor Metrorail Project (DCMP) involves the design and construction of a 23.1-mile extension of the Washington Metropolitan Area Transit Authority (WMATA) rail system. The initial 11.7-mile extension, with five transit stations and a new service and inspection yard, is to be constructed. The construction plan for the initial 11.7-mile extension includes installation of a total of an estimated 4,250 or 160,000 linear feet of driven 12x53 steel H-Piles at more than 80 different locations. At the time of this paper, approximately 40 percent of the piles have been installed and the remainder of piles will be installed by the end of 2010. This paper describes: 1) subsurface investigation program, 2) application of existing Codes and impact on the design of H-Pile, 3) design methods to determine geotechnical bearing capacity and pile tip elevation, 4) verification of capacity including PDA and Static Load Tests, 5) project specific pile load tests, and 6) QA/QC during pile driving.

Jan 1, 2010

By Roger Frank

"Abstract After noting the importance of standardization for piles, the European system is described (execution, tests and design, etc.). Some important aspects of Eurocode 7 are outlined (like the role of pile load tests). Finally, the calculation methods in the recent French standard for the design of piles following Eurocode 7 are shortly addressed.Importance of standardization for piles Like for other fields of geotechnical engineering, pile engineering is a complex art. For piles, the challenges are particularly numerous and many things must be mastered properly: - the soil investigation must be serious and adequate (for instance, deep enough!);- the choice of the pile type and the assumed behaviour must be assessed in order to reach a safe and economic design of the overall foundation;- the execution itself (construction and/or installation) deserves special attention and must follow strict state-of-the art rules.The geotechnical engineer, in charge of the design of a pile foundation, must have in mind the parameters linked to the variety of soils, of soil conditions and of pile types. A wide range of strong environmental issues are also to be considered: minimum disturbance during the execution processes, long-duration friendliness of the “inclusions” into the ground (to avoid pollution of the soils and waters, for instance) and respect of the neighbouring structures.Pile engineering plays in a world which is constantly moving and progressing: constructions expand in new difficult areas, actions on piles are more and more important, new execution techniques of piles are developed, research into the complex behaviour of pile foundations has no end, etc. Our views on how piles and group of piles really work are constantly evolving!"

Jan 1, 2014

By Paul J. Axtell

Two new railroad bridges in Kansas City, Missouri are founded on drilled shafts embedded into the soil and underlying shale. The uncertainty arising from the non-homogeneous, anisotropic nature of most shales, and the variability of shales across the U.S., makes it a difficult material to assign appropriate design properties. As was the case on this project, the uncertainty of foundation performance in shale can lead to overly conservative designs, particularly with drilled shaft foundations. An extensive Statnamic axial testing program was performed to verify that the load-settlement behavior of the drilled shafts would be acceptable for the intended railroad traffic. Axial Statnamic testing was applied in three increasing cycles of 927 kips, 1007 kips, and 3177 kips, respectively. The maximum movements recorded at the shaft head during each of the loadings were 0.052 inches, 0.062 inches, and 0.257 inches, respectively. The loads applied in each of the respective Statnamic tests were not sufficient to reach the capacity of the shaft; so direct comparison of measured and calculated capacities is not possible. However, evaluation of the estimated design capacity can be accomplished based on results from the Statnamic testing program by utilizing normalized load transfer relations presented by O?Neill and Reese (1999). Such comparisons necessarily require extrapolation of the data measured in the Statnamic tests following typical load-displacement response. Results indicate the Kulhawy and Phoon (1993) method for estimating side resistance in Pleasanton shale rock sockets, assuming a smooth socket, appears to agree well with observed behavior during Statnamic testing. Accordingly, the O?Neill and Reese (1999) method for estimating the toe resistance in intermediate geomaterials, assuming cohesive rock with Rock Quality Designation (RQD) between 70 and 100, appears to agree well with observed behavior during Statnamic testing. Finally, based on Statnamic testing at varying load magnitudes and normalized curves developed by O?Neill and Reese (1999), the contribution of side resistance to the capacity of a deep foundation can be determined assuming no load is transferred to the base of the foundation during lower magnitude testing. Furthermore, higher magnitude testing can provide a means to evaluate the accuracy of design end bearing calculations.

Jan 1, 2006

By Anil Bhandari

Using subsurface data collected at each drilled shaft location is an ideal approach for conducting drilled shaft design. However, conducting subsurface tests at each drilled shaft location and subsequently performing the drilled shaft design can be a daunting task for a noise barrier wall that is divided into six (6) sections and stretches for approximately four (4) miles. In addition, having individual drilled shaft designs complicates the construction process. Grouping the subsurface conditions into broad categories and performing the design for each of those categories is an attractive alternative to the design per boring approach. Currently there are no existing guidelines to aid a designer on grouping the subsurface conditions for the drilled shaft design for the noise barrier walls. Therefore, a method was developed based on the Standard Penetration Test (SPT) N values of the near surface soils to categorize the soil profiles into distinct categories. Since the soil engineering properties of the near surface soils are known to be critical for drilled shaft lateral capacity, these soils were emphasized in the methodology. This method was successfully implemented for the design of drilled shafts supporting the noise barrier walls along the I-20 in Columbia, SC. For this project, two distinct soil profiles, labeled as ?strong? and ?weak?, were used. An overview of the soil profile grouping methodology is presented as well as the vertical and lateral drilled shaft capacity analyses for this project for the two general soil profiles. The analyses indicated that the axial capacity governed the design in the ?weak? soil profile and the lateral capacity controlled the design in the ?strong? soil profile. However, this is not a generalization and whether the axial or the lateral capacity governs the design of drilled shaft depends on the soil profile and design loads. Nonetheless, our findings emphasize that both lateral and axial capacity should be checked for drilled shaft design even when the vertical load are minor.

Jan 1, 2011

By D. M. Holloway

As a part of the 1-15 Reconstruction Project, static and dynamic (high-strain) testing methods formed the basis to estimate long-term axial capacities, and to assess the magnitudes of bearing capacity gains (setup) from the end of installation to the time of static/dynamic tests weeks later. This paper summarizes the results of nine full scale pile load tests to failure in compression, and how the designers used these data to finalize pile selection and penetration criteria bridge-by-bridge in the final design stages. Soil conditions along the project alignment ranged from deep, lightly over-consolidated Lake Bonneville clays interbedded with granular strata of varying consistency, to sites dominated by dense alluvial deposits of cohesionless soils well above the water table. The test sites were selected to bracket the conditions that are expected. Twelve-, 16-, and 24-inch-OD pipe piles are to be used to support the new bridges. The team plans to impact-drive all piles closed-end to final penetrations. The test piles varied from 35-ft-long pipes driven to refusal in the shallow dense sands at some sites, to 115-ft-long pipes stopping at 3 blows per foot in predominantly cohesive deposits. The capacities gained with time proved to be reasonably predictable, and significant setup was noted both in the cohesive and cohesionless strata. The test program objectives included providing the means to estimate long-term capacities from short-term (24- to 48-hour) restrikes following installation of foundation piles during production driving operations.

Jan 1, 1998

By J. L. Goen

The Saint Joseph Hospital of Bellingham is located on a site underlain by glacial outwash. The construction of a five-story tower addition above an existing two-story wing was supported by five large trusses that impose a 1600 kips (7117 kN) column load on five pile caps in the courtyard of the hospital and on the new pile caps inside the existing MRI laboratory. The exterior columns of the trusses and the new parking garage addition were supported on conventional auger cast piles installed with conventional equipment. Helical Pulldown® micropiles were selected for use in the courtyard and the MRI laboratory because lightweight installation equipment (maximum unit weight of 7.5 kips (33.3 kN)) had to be used and it was required that no spoils be produced. The installation equipment was lifted into the courtyard by the jobsite crane. Sixty Helical Pulldown micropiles were installed for the pile caps in the courtyard. The pile caps inside the hospital were supported on 240 Helical Pulldown micropiles. Initial compression test indicated an allowable load for the micropiles to be 55 kips (244 kN). However, retest at a later date resulted in an increased allowed design load to be 85 kips (378kN) reducing the number of micropiles required by more than fifteen percent.

Jan 1, 2004

By Jean-Louis Briaud

The following is a summary of a very recent report prepared at Texas A&M University for the National Cooperative Highway Research Program and entitled "Downdrag on Bitumen Coated Piles". Anytime the soil settles more than the pile, downdrag or negative skin friction will develop. The load in the pile increases with depth up to a certain point and then decreases down to the pile point. This phenomenon has been quoted as being the number one culprit for deep foundation failures. In Chapter 1, an introduction to downdrag is given. The most common criterion for downdrag is to consider it in design as soon as the settlement of the soil surface after pile driving exceeds 0.5 in. Coating piles with bitumen is an effective way of reducing downdrag forces and therefore allows to use smaller piles for the same load. This results in cost savings. Coating piles with bitumen increase the cost of piles by about 33% and therefore the decision to use bitumen is generally based on economic considerations.

Jan 1, 1989

By Zhitao Ma

The Cast-in-place Concrete thin-wall Pipe pile, referred to as PCC pile, is a new kind of pile for soft ground improvement. In this paper, firstly, the general introductions of the new pile technique, mainly including the technique principle, the structure of pile-driving machine, and the technological process were given, then based on the results of in-situ static lateral loading test, the pile lateral capacity, the relationship of load-deflection of pile at the ground surface, the lateral deflections versus depth and the soil reaction along the pile shaft were analyzed.

Jan 1, 2006

By Jean J. Abiassi

The Boston Marine Industrial Park (BMIP) VENT 6 project is a cut and cover tunnel, part of the Central Artery / Tunnel (CA/T) in the city of Boston. The BMIP job will serve as the south approach to the Third Harbor Tunnel crossing. The alignment is approximately 2500 Ft long and is made up of four sections starting from west to east: 1. West Tunnel 2. Boat Section 3. East Tunnel 4. Tunnel inside Vent 6 Cofferdam and connection to the Third Harbor Tunnel. The support of excavation (SOE) system for the West Tunnel, Boat Section, and East Tunnel are all a part of this project whereas the SOE for Tunnel inside the Vent 6 Cofferdam was a part of the contract for the Third Harbor Tunnel.

Jan 1, 1994

By Yu Zhenquan

At the construction site of Bao Shan Iron &. Steel Mill in Shanghai, lots of RC driven piles with length of 50 to 60m were applied. The most unfavourable distribution of stress along the pile shaft was known by measuring the compressive and tensive stresses. With analysing the test results a phenomenon of impact fatigue of RC pile was discovered, the range of impact fatigue and its critical zone can be distinguished. Finally some countermeasures are presented to avoid the impact fatigue of RC long pile.

Jan 1, 1991