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By Lisa R. Papandrea, David Chen, Walter E. Kaeck

"Construction of the University at Buffalo’s new School of Medicine and Biomedical Sciences (UB-SMBS) required excavation in variable ground to a depth of more than 40 ft adjacent to the NFTA Metro subway and Allen Street Station. Complicating the building design and construction, the new medical facility incorporates the at grade Station entrance building, requiring a combination of temporary and permanent excavation support structures, a complex sequence of ground support installation, and a mix of shallow and deep foundations to accommodate the large floor spans and concentrated column loads introduced by building over and adjacent to the Station entrance. Excavation and foundation construction was challenged by a stratified soil profile with interlayered and sensitive sands, silts and clays and complicated groundwater regime with perched and regional water tables. Efficient construction required ongoing coordination between the design team and contractor, careful field observation, and construction monitoring in several facets of below grade construction. This paper describes the design and construction of excavation support structures and foundations to manage the variable ground, congested site conditions, and complications of building adjacent and above an active subway station. Use of site instrumentation and monitoring data to provide guidance in construction when unanticipated field conditions arise is illustrated. Lessons learned in installation and sequencing of excavation support, groundwater control and foundation construction are also discussed.INTRODUCTIONUniversity at Buffalo President Satish K. Tripathi heralded the new School of Medicine and Biomedical Sciences (UB-SMBS) as a future linchpin of UB’s downtown campus that will revitalize the area and enhance western New York’s emerging bio-sciences corridor. The $375 Million, 628,000 square foot, eight story building with two basements is expected to house 2,000 faculty, student and staff allowing UB to increase class size from 140 to 180 students. It will be constructed above the Niagara Frontier Transportation Authority’s (NFTA) Allen Street Station, creating a direct connection to Buffalo’s light rail system. The 200 ft x 400 ft site is bounded by Main Street, High Street, Washington Street and the Roosevelt Apartments and adjoining parking lot at the west, north, east and south respectively, as shown in Figure 2. Groundbreaking for the new building was in October 2013 with the facility scheduled to open in early 2017."

Jan 1, 2016

By Danielle Nhanqulumanga, Pranith Bhatt, Snehal Patel, Khadeeja Priyan

The Bi-Directional Static Load Test (BDSLT) is a test that determines the capacity of piles when loaded under bi-axial static compression. In recent years the BDSLT has seen an increase in demand due to its safety, speed, and affordability. This innovative foundation testing method has been universally used over the last 50 years, however respective codes and standards have only been published within the recent years. Detailed test procedures and methodology are expatiated in the ASTM D8169 M-18 [1], and the IRC 78 2014 Clause 709.2.5. [2] These standards provide the minimum requirements for the execution of the BDSLT. In this paper we did a comparative study of both standards envisaging to bring attention to the similarities and discrepancies found therein, with an aim to highlight the impacts and challenges that differing provisions of each standard could pose on the conduct of the BDSLT. Discrepancies found have been explained on the basis of geotechnical engineering theories and relevant field occurrences observed by superior engineers. Additionally, we emphasize on the relevance of experienced engineer’s judgement when utilizing the standards.

Sep 1, 2022

By William H. Walton, Joel Dellaria, Jeffrey R. Hill

The City of Chicago has a world-renowned skyline and is known for its provocative architecture. The subsurface conditions in the city have allowed for construction of these significant structures. The skyline is supported on caissons as they are called in Chicago or drilled shafts in other locations. Despite the significant strides the industry has made in advancing the drilled shaft, the use of other specialty geotechnical construction techniques like micropiles has not been overlooked in Chicago and the surrounding areas. Micropiles have been utilized to underpin famous existing historic structures like Orchestra Hall any many others. Engineers have used 200 to 600 kip micropiles to underpin compromised, inadequate, or damaged caissons. The paper will discuss the use of drilled shafts, micropiles, and ground improvement over the last 30 years in Chicago using a curated collection of case histories. It will also examine advancing the industry beyond its current technical limitations using these techniques. INTRODUCTION 20,000 years ago, glaciers from the Chicago region left behind sheets of glacial clay till underlain by dense, over consolidated glacial till below: limestone bedrock, found about 100 ft below street level. An unusual feature in this profile is the soft Chicago Blue Clay. Chicago has been called the birthplace of the Skyscraper and drilled shaft foundation, both of which came about in the 19th century. After the Great Fire of 1871, tall new structures were built rapidly and designing a successful foundation was trial and error. The first deep driven wood pile and caisson foundations bypassed the problem layer and found solid support on hardpan till or bedrock below (Schock and Risberg 2013). Once the drilled shaft foundation became acceptable to the Chicago engineering and construction community, building heights and complexity grew dramatically. As the city grew, building foundations were being repurposed. There was also the need to underpin structures for additional loads and shallow foundations for adjacent construction. Hand-dug drilled shafts were an option for some of these restricted access and low headroom sites but a new technique, micropiles, would prove to be the future of retrofit and hard to construct foundations. Micropiles were introduced on a limited basis to the United States market in the 1970s and 80s. In the early 1990s, the Chicago market began to latch onto micropiles and their use has grown significantly as a solution to the most complex foundation problems a maturing skyline has to offer.

Jan 1, 2019

By Musbah A. Hasan, Ahmed M. Nasr, Fauzi Jarushi

Many transmission towers, high-rise buildings and bridges are supported by piles. These structures may be subjected to large lateral loads. Therefore, experimental investigations on model piles under lateral loads were conducted in uniform dry sand. Small-scale model tests were carried out considering the influence of pile length, pile diameter, sand density, roughness of pile surface and vertical load on the lateral resistance of a pile. Furthermore, the effect of pile load eccentricity (e/L) on the ultimate lateral resistance was studied. Investigations, of the influence of various parameters on the magnitude of the coefficient of subgrade reaction (nh), were also performed. It was found that the lateral load capacity of piles increases with increase in pile length, pile diameter, pile surface roughness and increase in the sand density. The results also showed that the coefficient of horizontal modulus of subgrade reaction, (nh), decreases with deflection increase. From the results, the coefficient of subgrade reaction for a smooth pile embedded in medium dense sand would decrease by (134%) when the lateral pile head deflection (yg) changes from (2% to 5%) of pile diameter.

Jan 1, 2017

By Sumantra Sengupta

"Northeast Frontier Railway (NF Railway) intends to connect Imphal, the capital of Manipur (bordering Myanmar) with Assam by railway link. They have planned a 125km long railway line that passes through steep rolling hills of Patkai region, eastern trail of Himalaya, and as a result large number of tunnels and bridges need to be designed. While the high mountains are penetrated by tunnel, the deep gorges between the mountain ridges are connected by tall bridges. The tallest of such bridges connects a gorge at about 140m above its bed level with an overall length about 700m at rail level. In all, five such bridges with tall piers are now under construction. With extensive study on possible alternate arrangement of the bridges considering the effect of high seismicity of the area, moderately to highly weathered siltstone/ sandstone as ground bed material, slope of the hills etc it was decided that bridge will be founded on 1.5m diameter bored cast in situ piles with length varying from 20m to 30m depending on the location. The substructures are RCC hollow pier and superstructures are steel open web through type girder of 103.5m span. Considering absence of any major construction work in the vicinity, it was decided that prior to design work, Site-specific spectrum study will be carried out and design will be carried out considering the varying stiffness of the tall piers, each of different height. Interesting results were obtained regarding behavior of piles under lateral loads generated by high seismic conditions. The paper discusses in detail the design of Pile foundations and the effect of bed material along the steep slope on which the piles are being constructed.INTRODUCTIONIndian Railway has undertaken the construction work of connecting the North-Eastern states of India through railway line. The major stretches of the area passes through hilly terrain and as a result the line passes through tunnels and bridges in succession. The tall mountains are being penetrated with tunnels and immediate after deep gorges are crossed with high level bridges. The entire area is under high seismically active zone. The bed material below the ground level of the sloped hill is 4 to 10 meter of mixed soil of sand, gravel, pebbles etc underlain by moderately to highly weathered sandstone, siltstone at the higher level and moderately weathered sandstone, siltstone at lower level. Considering all the aspects like constructability, maintainability, geological and geotechnical aspect, seismicity, stability, safety, functional aspect and cost it was finally decided that the bridges will be simply supported structure with open web through type steel superstructure of maximum span 103.5m and hollow cylindrical discretely varying RCC substructure with 1.5m diameter group of piles as foundation. The paper discusses on the design aspect of the pile foundation in the rocky strata in the hill slope. The codes and standards that have been followed for design are IRS (Indian Railway Standard), IS (Indian Standard), IRC (Indian Road Congress), AREMA (American Railway Engineering and Maintenance-of-way Association), UIC (International Union of Railway) provisions."

Jan 1, 2015

"1.0 INTRODUCTIONThese Guidelines reflect the state-of-the-practice of the Deep Mixing Method (DMM) in North America. DMM is an in situ mixing process that breaks down the soil structure; injects binders, fillers and reagents into the soil; and blends them with the soil. DMM is also commonly referred to as Soil Mixing. The final properties of the treated soil in situ are a function of the composition of the native soils and groundwater, the binders introduced, the mixing methods and energy, and the conditions and time of curing. Treated soils generally have increased strength and stiffness and/or reduced permeability relative to the native soils.This document addresses DMM performed by rotating single and multiple axis mixing tools, rotating cutter wheels at the end of a rigid kelly bar, or trench mixing using a rotating cutting/mixing chain around the perimeter of a rigid bar. Binder may be injected through low or high energy (velocity) jets.The treated soils created through wet DMM are heterogeneous mixtures of binder, water, soil, and groundwater. Treated soils produced by dry DMM techniques are a mixture of binder, soil, and the water already present in the native soil.DMM applications described in this document include•,Earth retention•,Liquefaction mitigation•,Groundwater seepage control and containment isolation•,Bearing capacity improvement•,Deep foundations•,Mass stabilization and contamination containment•,Embankment, levee and dam strengthening, and stabilization•,Casing replacementThis document was developed to address deep foundations applications. Use of deep mixing for seepage control is not specifically addressed. The reader is referred to documents prepared by the U.S. Army Corps of Engineers for additional information. Shallow soil mixing and the use of DMM for stabilization/solidification of contaminated soils performed at depths less than 10 feet (3 m) are mentioned briefly. Jet grouting is not covered by these guidelines."

Jan 1, 2016

By Claudio Asioli

"The project’s goal was to construct the Al Ghazala Intercontinental, a multi-use development in the bay area of Tripoli overlooking the Mediterranean Sea. The site of the project is located approximately 500 ft (150 m) from the Mediterranean coast, near the Al Ghazala roundabout in the town center of Tripoli, Libya. The investor of the project was Magna Properties Group, Ltd. – Libya, the main contractor was Man Enterprise S.A.L., and the design and construction management was performed by Dar Al-Handasah Engineering. Trevi S.p.A. was contracted to perform the design and construction of the anchored diaphragm walls and dewatering systems for the excavation of a two-level basement car park, which extends across the full footprint of the site.The site was approximately 640 ft by 230 ft (195 m by 70 m) in plan and nearly flat. The groundwater level typically varies from about 11 ft to 23 ft (3.4 m to 7.0 m) above mean sea level. To construct the required raft foundation, it was necessary to excavate the area down to El. -15.7 ft to -26.3 ft (-4.8 m to -8.0 m), which resulted in an excavation depth ranging from about 27 ft to 39 ft (8.3 m to 12.0 m) below the existing ground surface.Subsurface ConditionsThe subsurface site investigation was performed in three phases by Al-Tamier Engineering Consulting Bureau. During Phase 1, a preliminary investigation was undertaken during the early stages of the project to obtain information about the general stratigraphy and groundwater level at the site. Phase 2 was performed to obtain subsurface information and design parameters, and Phase 3 was performed as a supplementary ground investigation to investigate unexpected ground conditions identified during Phase 2. In total, 14 boreholes were drilled to depths ranging from about 80 ft to 180 ft (24 to 55 m). The generalized subsurface profile is quite heterogeneous, and is predominantly composed of sand with silt and gravel that is underlain by limestone, calcarenite and claystone"

Jan 1, 2017

By Mohamed A. Sakr

An experimental study on the behavior of pile group's arrangement under lateral load was carried out in the level ground and at crest of sand slope 3H: 2V. Tests were conducted on single pile and pile groups with center-to-center pile spacing of 3D. The model piles were founded in sand with relative density 25%. Several configurations of pile groups were used to study the effect of piles arrangement in the group (series or parallel) with respect to slope crest. The behavior of the pile groups in the level ground was compared with the behavior of pile groups at different configurations at the slope crest. Based on the test results, the behavior of laterally loaded pile groups adjacent to a slope crest depends largely on piles arrangement in the group with respect to direction of the lateral load. Pile groups in the level ground have more resistance to lateral loads when they are arranged in a parallel configuration than in a series, whereas the reverse is true in cases of pile groups constructed near to the edge of a slope. It is advisable to use the pile group in series arrangement for groups constructed at slope crest to minimize the effect of the ground slope on lateral capacity of piles and the occurred deflection and maximum bending moment of the lead row in the group.

Jan 1, 2010

By Christopher R. Harris

"Considerations are presented for developing and implementing self-hardening slurry mix designs to be utilized in barrier seepage walls. Slag-cement-cement-bentonite (SCCB) slurries are the primary focus, with some comparisons referenced to the more traditional Portland-based cement-bentonite (CB) slurries. Field and laboratory mixing methods are reviewed, including 1) single sack – single mixer method; 2) bentonite slurry mixer – cementitious addition mixer method; 3) bentonite mixer – grout mixer – CB blending mixer method. Major phenomena associated with the dynamics of barrier wall excavation, such as loss of water from the in-trench slurry and consolidation of in-trench slurry are discussed. Other topics touched upon include sand content effects, fluidizers utilized, and chemical contaminants. The role of higher bentonite to water ratio is reviewed, with demonstration of improvement of filtration properties, and an increase of water retention of the final consolidated product.IntroductionSelf-hardening slurry has been utilized to construct barrier seepage walls for many decades. This is essentially a single-step slurry excavation and backfill process whereby the trench-supporting fluid gains strength over a short period during installation and maintains or develops low hydraulic conductivity. The resulting curing slurry becomes the actual barrier wall as the resultant cement-augmented clay slurry now fulfills the dual purpose of both temporary trench stabilization and final cured-in-place product. This eliminates the requirement and expense of subsequent backfill/slurry displacement operations required in traditional barrier wall installations.Self-hardening slurries have been fabricated using a number of various clays, most commonly sodium bentonite, calcium bentonite, attapulgite, and sepiolite. Perhaps due to plentiful high quality sodium bentonite deposits found domestically, the proven excavation stabilization properties imparted from sodium bentonite slurries, sodium bentonites are typically specified for formulating self-hardening slurries in the US. Cementitious materials utilized most commonly are Portland cement and slag (ground blast furnace slag or GBFS). For the purposes of this discussion, self-hardening slurry having a cementitious of Portland will be referred to as CB. Those having cementitious material of GBFS replacing Portland (partially or wholly) will be referred to as SCCB."

Jan 1, 2016

By Claudio Asioli

"The project’s goal was to construct the Al Ghazala Intercontinental, a multi-use development in the bay area of Tripoli overlooking the Mediterranean Sea. The site of the project is located approximately 500 ft (150 m) from the Mediterranean coast, near the Al Ghazala roundabout in the town center of Tripoli, Libya. The investor of the project was Magna Properties Group, Ltd. – Libya, the main contractor was Man Enterprise S.A.L., and the design and construction management was performed by Dar Al-Handasah Engineering. Trevi S.p.A. was contracted to perform the design and construction of the anchored diaphragm walls and dewatering systems for the excavation of a two-level basement car park, which extends across the full footprint of the site.The site was approximately 640 ft by 230 ft (195 m by 70 m) in plan and nearly flat. The groundwater level typically varies from about 11 ft to 23 ft (3.4 m to 7.0 m) above mean sea level. To construct the required raft foundation, it was necessary to excavate the area down to El. -15.7 ft to -26.3 ft (-4.8 m to -8.0 m), which resulted in an excavation depth ranging from about 27 ft to 39 ft (8.3 m to 12.0 m) below the existing ground surface. Subsurface ConditionsThe subsurface site investigation was performed in three phases by Al-Tamier Engineering Consulting Bureau. During Phase 1, a preliminary investigation was undertaken during the early stages of the project to obtain information about the general stratigraphy and groundwater level at the site. Phase 2 was performed to obtain subsurface information and design parameters, and Phase 3 was performed as a supplementary ground investigation to investigate unexpected ground conditions identified during Phase 2. In total, 14 boreholes were drilled to depths ranging from about 80 ft to 180 ft (24 to 55 m). The generalized subsurface profile is quite heterogeneous, and is predominantly composed of sand with silt and gravel that is underlain by limestone, calcarenite and claystone."

Jan 1, 2017

By Brian T. Nereson, Michael C. Penney

"This technical paper was prepared to describe the general process by which the authors designed a column-supported load transfer platform (LTP) for support of asphalt-paved runway and taxiway embankment areas over soft organic soils, the major tasks and observations made during construction of the system, and the outcome of the system design and construction. The LTP system was designed using the method described in the BSI Standards Publication Code of Practice for Strengthened/Reinforced Soils and Other Fills, BS 8006-1:2010 (BS8006), to achieve performance objectives for the project. The design also used other criteria based upon the authors’ engineering experience and understanding of the expected interaction between soils, structures and geotextiles. The design and construction process described herein resulted in a successful project. The authors identified that full-time engineering oversight during construction was of high importance and provided a high degree of value to the project. The authors’ intimate knowledge of the potentially adverse effects of variations in construction practices promoted timely identification of construction deficiencies that could have affected the reliability of the system. This resulted in corrections and modifications being made, while materials were still accessible, to protect the intended performance of the finished system.INTRODUCTIONThe site is located in Marshfield, Massachusetts. The surrounding area is flat and contains significant wetlands with a water table at or near the ground surface. Prior to the improvements described herein, the site was already developed as an existing municipal airport with an approximately 3,000 linear-feet asphalt-paved runway oriented in a northeast/southwest direction (northeast end referred to as Runway 24 and southwest end referred to as Runway 6; Fig. 1). The site is located approximately 0.5 to 1 mile (Runway 24 and Runway 6, respectively) from the Atlantic Ocean.The improvement project included total extension of approximately 550 linear feet of asphalt-paved runways and taxiways over existing wetlands that consisted of soft, organic soils with varying but significant depths (Fig. 2). An initial geotechnical assessment performed for the project identified that the subsurface conditions were not suitable to support the proposed runways and taxiways in their existing state."

Jan 1, 2016

By W. G. K. Fleming

Mr P. Bermingham introduced paper 9.1, describing the development and trials of a new pile load-testing technique that the Authors had termed "Statnamic". The system involved launching a test weight mounted on the head of the pile by igniting chemical fuel in a pressure combustion chamber between the pile head and the test weight. The expansion products from the burning fuel generated large pressures which were used to launch the weight upwards at high velocity. The reaction from this force generates an equal and opposite force at the pile head. This force is typically of much longer duration compared with, for instance, dynamic load testing by drop hammer. In addition the pile experiences a much lower acceleration - typically of less than one g. Because of the long duration blow, the pile is loaded at below its natural frequency and is therefore under a uniform high stress over its full length throughout the duration of the test. The pile behaviour is not dominated by the complex action of an impulsive stress-wave as with standard dynamic testing. The test technique is thus essentially quasi-static. It was anticipated that a ram test weight of 16 tonne would be sufficient to provide the test reaction for a 600 tonne load test. It was pointed out that the device was still at the research stage, but had yielded encouraging results to date. Testing would proceed from model testing and computer simulation to full scale field testing.

Jan 1, 1991

By Ed Revoort, Robert Schippers

In Rotterdam in the Netherlands the project ‘De Zalmhaven’ is being developed. The project consists of the realization of houses, parking facilities, two residential towers of 70 m and a residential high rise of 215 m. An artist impression for the project is given in figure 1. For the high rise a new development in the use of large diameter, drilled piles with a steel casing has been successfully utilized. In this article the installation method of 65 m long steel drilled piles in two consecutive sections is presented. The settlements for the building (and the influence on its surroundings) have been analyzed in detail using 3D Finite Element calculations, which will also be discussed. Finally there is focus on the results of settlement measurements carried out during construction in relation to the settlement prognosis.

May 1, 2022

Jan 1, 1996

By John P. Turner, Benjamin J. Turner

"This report describes a research project for evaluating the applicability of the widely accepted 80 percent criterion for elongation of ground anchors to anchors with unbonded lengths exceeding 100 feet. This issue is driven by several recent projects involving ground anchors for landslide stabilization in which a significant percentage of the anchors did not meet the criterion that requires measured elongation during proof load testing of at least 80 percent of the theoretical elastic elongation. The projects involved anchor unbonded lengths in the range of 85 to 220 feet, which is outside the range traditionally used in practice, although anchors of this length are being used more frequently for landslide stabilization. The principal objective of this research is to address whether the widely accepted criterion of 80 percent elongation is applicable for such applications, and whether other factors affect the ability of anchors to meet the criterion.Analytical methods for predicting transfer of load along the length of steel strand due to friction loss are used routinely in the prestressed concrete industry. These analytical expressions provide a rational framework for quantifying changes in load due to friction along the length of a ground anchor in terms of a ‘wobble coefficient’ (K) as defined in Aalami (2004). Values of the wobble coefficient for ground anchors can only be determined by back-calculating from load tests, i.e., fit the value of K to the appropriate analytical expression based on the known test load and measured percent elongation. The analytical basis is first developed and shown to provide a tool for evaluating results of anchor load tests to determine the magnitude of expected elongation as a function of unbonded length. Next, a database of anchor load tests is used to back-calculate values of K for anchors with unbonded lengths in the range typically used in geotechnical applications (< 100 feet). These values of K are then used to calculate expected friction loss for anchors with high unbonded lengths (100 to 250 feet) to evaluate whether the 80 percent criterion is reasonable."

Jan 1, 2017

Jan 1, 2003

By Alfred H. Brand

New York City contains extensive deep deposits of glacial lake varved silt and clay, often overlain by organic soil. An 18 story building was proposed for Manhattan&apos;s upper East Side in one such area where bedrock is approximately 200 ft deep. Various pile and caisson alternatives were considered extending through the glacial lake soil to rock, but all proved beyond the project budget. Laboratory testing showed that the glacial lake deposits were preconsolidated. A test pile program using auger cast piles bearing in the glacial lake deposits proved that such piles could safely carry a load of 60 tons per unit. The auger cast pile scheme was estimated to be more economical than a deep pile alternative. A further benefit was that the vibration-free pile installation procedure posed less risk to adjacent structures which had been founded at shallow depth in fill above organic deposits and were stressed and cracked due to prior settlement. The project was designed with the anticipation that the glacial soils beneath the tips of the piles would produce a building settlement of 1 to 2 inches. The building was constructed in 2001 and 2002. It has been completed and is now occupied. Settlement data show that the building is performing as predicted. The auger cast pile scheme founded in a compressible stratum has proven to be successful and is a very unusual foundation alternative.

Jan 1, 2003

Jan 1, 1995

Jan 1, 2001

This Workshop was held at the Doubletree Inn, Seattle, Washington from September 26 to 28, 1997. Run under the auspices of the Deep Foundations Institute (DFI), it was co-funded by the newly formed Japanese Association of Micropiles (JAMP), and the Federal Highway Administration (FHWA). The Workshop was jointly organized and facilitated by Fujita Research Corporation and ECO Geosystems, Inc., with close support by Donald B. Murphy Contractors, Inc. DFI kindly consented to publish these Proceedings. As is clear from the list of attendees, 42 specially invited engineers from all aspects of micropile technology were present, representing Japanese, European and American practice. This proved to be a most friendly and interactive group of people, who freely exchanged ideas, views and close comradeship, not only during the technical sessions, but (and especially!) during the numerous social events. Perhaps the best illustration of this came in Day 2 when the attendees were divided into five competing teams, each comprising representatives from the different geographic groupings. These teams had to quickly devise solutions to two technical problems (using standard data previously provided. A team of "referees" (who also acted as "coaches") later determined the most apposite response, based on constructability design concept, cost, schedule and so on. Not only were the winning team very liberal in distributing the prize (vintage California champagne) among themselves, but the whole Workshop soon benefited from their generous division of the spoils of victory.

Jan 1, 1997