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By Kenneth A. Pidgeon

This paper presents a case history on mitigating vibration problems associated with the installation of steel sheetpiles. The project in-cludes installation of steel sheetpiles for a utility trench within 40 feet (12.2 meters) of a very sensitive manufacturing facility. Numerous production line quality control instruments and manufacturing processes within the manufacturing facility are extremely sensitive to vibrations. To minimize the impact to the owner, we specified that the contractor perform a vibration study using different types of pile hammers. The results and conclusions of the vibration study are presented in this paper.

Jan 1, 1995

By Zaw Zaw Aye, Sereyroath Chea, Nutthapon Thasnanipan, Thayanan Boonyarak

"As there are only limited numbers of bored pile constructed in sandstone and siltstone in Thailand, load transfer and settlement behavior of a pile in these rocks are still not fully understood. Major factors which influence the performance of the pile in the sedimentary rock should be systematically investigated. The objective of this paper is to analyze load distribution and load-settlement behavior of bored pile in sedimentary rock. Interpreted data was obtained from instrumented load testing results of large-diameter bored piles. These piles were drilled in aeolian soil and socketed in sandstone or siltstone, having socketed length varying from 1 to 3 times the pile diameter. Factors that influenced pile settlement behavior, consisting of rock type at the pile base, socket length, at-rest earth pressure and rock conditions, were analyzed. For interpretation of results, analytical solutions were used to estimate load bearing capacity and calculate settlement of each pile. According to test results of mobilized unit skin friction in siltstone, relationship of 0.1 – 0.3 square root of the unconfined compressive strength of rock appears to reasonably capture the measured shaft friction. Note that shaft movement in siltstone layer was not fully mobilized as maximum pile head settlement was still less that 1% of the pile diameter.INTRODUCTIONExtensive research of bored pile construction in soft soil in Thailand and Myanmar (Boonyarak et al., 2016; Aye et al., 2015) has been carried out. However, behavior of bored pile in weak rocks such as sandstone and siltstone is still not fully understood. Unit skin friction and unit end bearing of piles in these weak rock were reported by Horvath et al. (1983) and Pells and Turner (1980), respectively. Further research is still required to minimize variation in data presented in their study.This paper presents interpretation of load testing results of instrumented piles. These piles were excavated in aeolian deposit in the Northeast Thailand. Some piles were socketed in sandstone or siltstone. Analysis results of load-settlement, shaft shortening, pile settlement estimation, factor for calculating shaft friction and end bearing are reported. Discussion and explanation of pile behavior in sandstone and siltstone is provided.BRIEF INFORMATION OF THE PROJECTProject locationsThe construction sites are located in Khon Kaen and Nakhorn Ratchasima Provinces in the Northeast Thailand. Bored piles in this project were designed for supporting elevated structures for railways, overpasses and U-turn bridges for vehicles. These overpasses and U-turn bridges are distributed along the existing railways with the distance of about 180 km."

Jan 1, 1900

By Armin W. Stuedlein, Steven R. Saye

The differences between calculated axial pile capacity and the capacity realized during and following installation has long presented a significant concern for foundation engineers and contractors. Such differences have increased in prevalence with the increased use of larger diameter steel pipe piles and the significant increase in design-build contracting. The writers present concepts to close the gap between calculated axial pile capacity and the capacity realized during and following installation of driven pile foundations, including: (1) pile set-up in plastic soils, (2) limitation of re-driving of piles after setup which serves to reduce pile capacity, (3) the use of a vibratory hammer to install piles in cohesive soils disturbs the supporting soils and reduces the pile side resistance capacity significantly, and (4) long pile installation times for open-ended piles can damage the pile side resistance. Examples are presented from practice to illustrate these concepts and to guide pile installation planning to recognize the installation impacts and either consider alternate installation approaches or to properly consider the installation impacts during design.

By Vidyaranya Bandi, Madhav Madhira, Kota Vijay Kiran

"Using hyperbolic relationships for the non-linear responses of shaft and base resistances, a method is proposed for estimating initial shaft and base stiffnesses and ultimate shaft and base resistances of a pile from pile load test results. An iterative procedure is used to arrive at the values of shaft-soil and base stiffnesses and the ultimate shaft and base resistances. The method is applied to load - displacement data available from pile load test results to illustrate its efficacy.INTRODUCTIONA pile foundation is the most effective and economical solution in transferring large vertical loads to deeper depths. As the pile is subjected to axial load, the soil mass surrounding the pile is vital in providing vertical support for the pile. The nature of pile–soil interaction is three dimensional and to complicate the problem further, response of soil is nonlinear. Finding a closed form solution to such problem is extremely difficult. Several methods were developed to study and predict the response of the composite pile–soil system. Faruque and Desai (1982) implemented both numerical and geometric non-linearities in their three dimensional finite element model. Rajashree and Sitharam (2001) developed a nonlinear finite element model of batter piles under lateral loading using a hyperbolic relation for static load condition and modified hyperbolic relation, including degradation and gap for cyclic load condition.The ultimate capacity of the pile is estimated considering the strengths and unit weights of soil layers with depth, overburden pressure and other relevant parameters. The estimated capacities always need to be validated by conducting initial maintained load test. The estimated capacity may differ with the actual at site since the values of strength, stiffness, interface resistance between pile and soil, lateral earth pressure coefficient with depth and soil stratification, etc., differ from the design parameters considered for estimating the ultimate capacity of pile. The estimation of axial capacity of piles involves considerable uncertainties in selection of appropriate design parameters and the design rules are not always consistent with the installation procedures/processes involved."

Jan 1, 2017

By Dan Brown

A method is outlined for computing the contribution of a micropile group to global stability of a sliding mass. The forces in the micropile are computed in a way which accounts for the effect of soil mass movement on the mobilization of axial and shear forces and which maintains compatibility between shear and axial force as a function of displacement. The method provides a rigorous model to incorporate the pile forces into the stability calculations, including the effect of pile forces on the resultant shear and normal forces at the sliding surface. This paper demonstrates the proposed solution using a simple example slope.

Jan 1, 2007

By Michael A. McNicholas

"Deep foundations utilize the varying soil conditions to provide the most cost-effective or practical scope for a given jobsite. Once the scope has been determined and the engineering applied, the element can be installed and tested to determine if it is suitable. QA/QC programs are vital for the assurance that the element designed by the engineer has not only been properly constructed but that the design assumptions are confirmed. The two deep foundation elements referenced are drilled displacement piles (DDP) and micropiles. Each of these elements allows for large loads to be distributed deep into the subsurface geology. Having the technology and ability to monitor the tests in real-time can be beneficial to a contractor in determining if the design is adequate or if adjustments need to be made on future piles. The proper QA/QC guidelines for installation and monitoring need to be in place to ensure that an accurate interpretation can be made on the pile. This paper discusses the typical testing and the positive results that the author has encountered using the latest advances in strain analysis.KEY TERMSDrilled Displacement Piles:A deep foundation system that has the ability to shed load into the geology through shaft resistance as well as tip resistance, similar to drilled shafts. This pile element is unique in that it has a consistent pile section and thus a consistent modulus of elasticity.Micropile:A deep foundation system used in applications where the foundation lies over material not suitable for a spread footing and the ideal soil stratum is deep below the foundation. Micropiles will have two different cross-sections consisting of a cased section and an uncased section. For this reason, this pile type requires additional analysis when computing stress-strain relationships.Geokon Strain Gauges:Instrumentation such as Models 4911A-4911 Vibrating Wire Strain Gauges ( known as Sister Bars) are designed to be embedded in grout and calculate loads based on the change on grout strain over a period of time.Stress:A pile element is under a compression (axial loading) load when a force acts along its axis and is normal to the plane of the section. The corresponding stress the pile is experiencing is described as a normal stress. The stress is obtained by dividing the magnitude of the load distributed over the cross-section by the area of the pile cross-section, as shown in Eq. 1."

Jan 1, 2017

By Anthony T. C. Goh

"For deep excavations in soft clay, it is common to use jet grouting piles (JGP) prior to excavation to minimize wall deflections and ground settlement, and to prevent basal heave instability. In this paper, finite element analyses were carried out to assess the basal heave factor of safety for excavations in soft clay supported by JGP. Comparison of the factor of safety from the finite element analyses with limit equilibrium methods was then performed. Subsequently, to account for the uncertainties in the soil and JGP properties, a simplified reliability analysis procedure is proposed to estimate the probability of basal heave failure for deep excavations supported by JGP.INTRODUCTIONJet grout piles (JGP) are often used to prevent basal heave instability and to minimize excessive wall and ground movements associated with deep excavations in soft clay deposits (Shirlaw 2003; Wen 2005; Ou 2006). The jet grouting process which is carried out prior to any excavation works produces a series of short overlapping grout columns resulting in a “continuous” base slab (commonly termed as jet grout pile or JGP) below the final excavation level that spans across the entire excavation (Gaba 1990; Hsieh et al. 2003; Ho and Hu 2006). Typically, the JGP thickness ranges from 2 m to 4 m.The focus of this paper is on the assessment of basal heave instability for deep excavations in clay stabilized with JGP. Finite element analyses were first conducted to determine the basal heave factor of safety for deep excavations in clay with JGP. Comparisons were then carried out with factors of safety based on conventional limit equilibrium methods. Since the conventional factor of safety approach does not explicitly reflect the uncertainties of the soil and JGP properties, it is demonstrated in this paper that a simple reliability based approach (Hasofer and Lind 1974) can be used to assess the probability of basal heave failure.LIMIT EQUILIBRIUM METHODFor excavations is clay, the Terzaghi (1943), Bjerrum and Eide (1956) and Eide et al. (1972) methods which are based on bearing capacity theory, are commonly used to determine the basal heave factor of safety. Another commonly adopted method in Japan and Taiwan is the slip circle method which involves taking moments about the lowest strut level (JSA 1988; Hsieh et al. 2008; Luo et al. 2012). The slip circle method has also been applied for excavations with a JGP at the base by incorporating the undrained shear strength of the JGP. In the slip circle method, the basal heave factor of safety FSslip is assessed by taking moments about the lowest strut level (Fig. 1)"

Jan 1, 1900

By Zhang Jiaju

For the highrise buildings with deep foundstion of irregular plane shape, an appropriate calculate model to the heave of foundation soil after excavation is proposed and studied using analytic method and FEM (Finite Element Method) respectively to provide an effective way for solving this kind engineering problem. Also combined with the practice of construction deep foundation of Capital Mansion, calculation of the heave of foundation soil after excavation is given. Compared these results from above two methods with the results measured in situ, it is conformal on the whole, and the results by FEM are much closer with the measured.

Jan 1, 1991

By Y. Duraisamy

This paper presents the compressibility of tropical peat reinforced with cylindrical cement column. When a cement column installed vertically in peat, its compressibility was reduced because of the hardened skeleton matrix formed by cement particles bonding with adjacent soil particles in the presence of pore water. The effects of diameter, number of columns and cement proportions in cement columns on the compressibility have been investigated in this study. The results indicated that compressibility index Cc and Ca decreased with the increase in diameter of the cement column. Specimens with 45 mm and 60 mm diameter of cement column were cured for 28 days, after which they were subjected to Rowe Cell Consolidation test. Based on the results obtained, it shows that cement columns can successfully reduce the compressibility of tropical peat.

Jan 1, 2007

By B. M. Das

Several laboratory model test results for the determination of the ultimate uplift capacity of single and group metal piles embedded in near-saturated clay have been presented. Based on the uplift test results for single piles, the variation of the adhesion factor with the undrained shear strength of clay has been determined, and an empirical correlation for estimation of the adhesion factor in soft and medium clays has been presented. The group efficiency of piles under uplifting load depends on factors such as embedment ratio, undrained shear strength of clay, the number of piles in a group, and the center-to-center spacing of the piles.

Jan 1, 2010

By Chu E. Ho, Alfredas Daugiala, Nicola Ebanks

"The construction of an ancillary structure for the new Second Avenue Subway Line in Manhattan, New York City involved a deep excavation in highly variable rock conditions adjacent to a fragile masonry building. The maximum difference between the lowest and highest rock elevations was about 30 feet, which posed a problem for the installation of secant piles that formed the supporting retaining wall for the excavation. At certain areas, the rock levels were higher than the top of the invert slab of the ancillary structure. To avoid disturbance to the adjacent fragile building, the secant piles were fully cased for drilling through the overburden soils and the rock sockets were formed using non-vibratory technique. This paper discusses the design and installation details of the secant pile wall and the contingency measures that were considered to mitigate the highly variable rock conditions. Monitoring of the adjacent fragile building showed that impact of pile installation were controlled within tolerable limits and safety of the building was not compromised.INTRODUCTIONThe 96th Street Station forms part of the newly constructed Second Avenue Subway Line on the East side of Manhattan Island, New York City (Figure 1). During construction of this station, several deep excavations were carried out adjacent to existing fragile buildings (Arksman et al. 2012, Grigson et al. 2016). These fragile buildings were typically four to five stories high, with a single rubble wall basement supported on timber piles or seated directly on the fill. The timber piles were often found to be in a poor condition and connections to the footings were compromised due to rotting of the timber within the zone of water table fluctuation. Several of these fragile buildings had to be strengthened and underpinned to improve the stability of the structures prior to commencement of excavation for the new subway station box (Trabold et al. 2012, Ho and Pena-Iguaran, 2013). The situation was most challenging at Ancillary Buildings 1 and 2 located at 93rd and 97th Street respectively, where secant pile walls were located merely 2 feet away from the adjacent property line, due to architectural space constraints. While mitigation of excavation induced ground movements can be controlled by the adoption of a stiff excavation support system, a more concerning factor was the uncertainty associated with the impact of the secant pile wall installation on the stability of the existing fragile buildings. This was particularly difficult at Ancillary 1 where the secant piles encountered highly variable rock levels that intruded into the excavation space. The following sections discuss the design and installation of the secant pile wall and contingency measures that were considered at Ancillary 1."

Jan 1, 2016

By Chris Sammon

The Block 75 portion of the City Creek redevelopment project in Salt Lake City required multiple shoring walls surrounding the 6 acre site constructed to depths ranging from sixty-five to ninety feet below original street grade. Shoring for the project was challenging due to site soils consisting of cobbles, sands and gravels, interlayered lakebed silty clay and fine sandy silt with incised stream deposits of silty/clayey sand and gravels combined with a high groundwater table. Moreover, several abutting structures each with a unique foundation system would be directly or indirectly supported by the shoring system. Three sections of interest are the shoring walls constructed at Main Street, Deseret Trust Building and Eagle Gate Tower. Main Street shoring extended to as much as sixty-five feet below street grade and utilized existing basement walls anchored in place in the upper zones with soil nail walls with pre-installed vertical elements for face stabilization below. Data are presented which illustrates the effect dewatering had on the settlement of the Main Street Shoring. The Deseret Trust Tower shoring supported a 12 story, historical masonry building. Site conditions dictated a separate design for the east side and the north side of the building allowing comparison of relative performance between these walls. Settlements of this structure were controlled by installing micropiles through the 90 year old structures spread footings. Shoring for the Eagle Gate Tower was to be constructed immediately adjacent to a mat supported 22 story high rise structure. This shoring system combined secant piles, ground anchors and incorporated existing abandoned-in-place pipe piles with infilling high pressure jet grouting to create a cutoff wall and eliminate the adverse impacts of dewatering below this sensitive foundation.

Jan 1, 2010

By Joel Moskowitz

In 1990, the United States General Services Administration (GSA) issued a contract for design and construction of a new federal court building in New York City. Mueser Rutledge Consulting Engineers (MRCE) served as Project Geotechnical Engineers. The project site is in the historic government district at Foley Square. It is surrounded by the New York County Courthouse to the west, an existing federal prison building and federal courthouse across Pearl Street to the south and southwest, an office structure to the north, and a residential tower to the east. The interior of the site was crossed by streets which have now been demapped. As with many urban sites, this site was previously occupied by tenement buildings or industrial structures demolished near the turn of the century. Remains of old building foundations were exposed during construction excavation. In addition, buried fuel oil tanks servicing the adjacent courthouse were removed and the usual assortment of urban utilities had to be relocated for the new building foundations. Ground surface elevations vary from about 4.5 to 6 m above the local Mean High Water Datum Plane.

Jan 1, 1996

By Kenneth Gavin

Design practice for piles installed in Irish glacial till has developed in an ad-hoc manner, based on the results of un-instrumented load tests. This had led to designers using similar design parameters for both CFA and displacement piles. To address the concerns of industry a series of instrumented pile tests were performed by two Irish Universities. These tests summarized herein, revealed that CFA piles develop higher shaft resistance than piles driven in glacial till. However, they exhibit low base stiffness and the end bearing resistance that can be mobilized at acceptable pile settlement is low. The use of simple non-linear elastic design approaches to predict the load-displacement response is considered. The methods are used to predict the capacity of two large diameter CFA piles installed in glacial till. While the predictions were reasonably accurate at predicting the initial load-displacement of the piles, significant creep settlement developed at higher load levels. The cause of the creep settlement was investigated through the use of plate load tests and the consequences for pile design are discussed.

Jan 1, 2009

By S. Kanai

Nodular piles is to be piles provided with several nodular projections along the pile shaft, as shown in Fig. 1. Nodular piles are usually installed through either driving method with hammer or preboring method. This paper presents that the bearing capacity installed through each method is considerably higher than that of cylindrical pile without nodules. This paper also proposes the statistically analyzed unique formulae of the bearing capacity of nodular piles.

Jan 1, 1989

By Jose L. Garcia

The following document aims to cover all issues concerning the three main methods employed for the in-situ survey of concrete pile integrity. Within it are described both sonic coring and low-strain tests and the frequency and time domain analysis of their results, which are the most advanced techniques currently in use in Spain. The survey techniques described were developed and began worldwide deployment in the 1960s, but it was not until the 1980s that they saw large scale implementation in Spain, largely thanks to the miniaturisation of electronics and computer equipment that made them easier to use on-site. Sonic coring, echo and frequency-response testing or mechanical impedance tests are spreading further every day. However, there appears to be a need for standardisation of the testing methods, as well as their implementation, interpretation and the presentation of results. The goal of these Spanish recommendations is to serve as a guideline for test standards and to provide examples for a correct and commonly agreed interpretation of test results, as well as settling any differences in the evaluation of defects detected in foundation works.

Jan 1, 2006

By Charbel Khoury, Kwabena Ofori-Awuah, Kofi B. Acheampong

"Following heavy rains in spring of 2014, Prince George’s County officials issued a mandatory evacuation for homes in the Piscataway Hills subdivision of Fort Washington, Maryland where a landslide along a 1700-foot hillside destabilized homes, collapsed the single access road, and resulted in water and sewer mains break. Forensic investigations, including geologic assessments, test borings and in-situ Cone Penetrometer and Dilatometer soundings, were performed to evaluate subsurface conditions and provide stabilization options for the roadway and slopes. Post-failure ground movements were monitored using inclinometers. Critical failure planes were identified within the underlying 30-foot thick Marlboro Clay formation, a known geologic hazard with historic occurrences of landslides and slope failures.This paper discusses the remedial design for stabilizing the landslide and 60-foot hillside slope failure, and protecting the roadway. Amongst several feasible options, driven piles were selected in consultation with the County and retained contractor based on cost, environmental impacts and site constraints. Constraints included private ownership of hillside slope, upslope buildings safety; deep-seated failure, relocation of underground water and sewer mains, and accelerated construction schedule.Pile design included global slope stability analyses and lateral pile analyses using several loading configurations to optimize pile geometry and spacing, and determine a value-engineered design satisfying both serviceability and strength limit states to achieve long-term stability with factor of safety of 1.3. Soils within the active landslide plane were assumed to provide no resistance, while soils below the failure plane provided lateral resistance. This stabilization scheme, which extended along the 1700-foot roadway section and toe of hillside slope area, consisted of 410 steel HP16x141 piles in two to three rows driven to depths between 60 and 70 feet below the Marlboro Clay stratum at 5 to 7-foot spacing."

Jan 1, 2017

By C. L. Liao

The chief experiences for constructing deep tubular columns foundation under deep water are as follows: 1. P.C. tubular columns were sunk inside the caisson. 2. P.O. tubular columns of 3.6 M. diameter were sunk thru thick soil layer to a depth of 47 M. by vibrators. 3. The double wall steel cofferdam was sunk thru soil layer to a depth 31.3 M.. 4. Bore the bedrock with rotary drill succesfully. According to the successful experiences mentioned above, the deep tubular columns foundation may be constructed beyond 100 meters.

Jan 1, 2010

By Amalia Giannakou

This paper utilises 3-D finite-element modeling to study the static and dynamic lateral harmonic response of inclined piles, in a homogenous and a non-homogenous soil, modeled as a linear hysteretic medium. The results of a comprehensive parameter study are presented in the form of dimensionless plots of: (a) static and dynamic swaying and rocking stiffnesses and damping ratios, and (b) distribution of internal forces (bending moment, shear and axial force) with depth. These plots can be readily utilised in practical applications and they offer insight on the role of the inclination in the response of flexible piles.

Jan 1, 2006

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