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By Patrick O. Shires, Harry W. Schnabel

With stable building sites becoming scarce in the greater San Francisco Bay Area, the new Summit Senior Care Facility is being built into the side of an unstable hillside adjacent to the San Ramon Regional Medical Center in San Ramon, California. This hillside has had a long history of instability and the site of the new Senior Care Facility required excavation into both a historic old landslide and a more recent active landslide. After a thorough geotechnical study, it was concluded that the best way to build the new facility would be to construct a tied-back retaining wall in the area of the old landslide, since it extended off-site onto two adjacent properties, and remove the active landslide and replace it with compacted fill before cutting into its toe area with an additional tied-back retaining wall. The design was further complicated by the proximity of the site to several active faults. In the area of the old landslide, the combination of an ascending slope behind the wall, landslide forces and seismic forces resulted in total design pressures between 365 to 4,575 PSF for a wall with a maximum height of 30 feet. The wall for the old landslide was constructed by first drilling and placing steel soldier piles in concrete. The tip of the soldier piles extended a minimum of 12 feet below the landslide plane that was up to 36 feet below the bottom of the wall. Permanent double corrosion protected tiebacks were then installed through the soldier beams and anchored below the slide plane. A shotcrete facing was then installed on the face of the wall. BACKGROUND The site of the Summit Senior Care Facility is located on the southwest flank of Mount Diablo adjacent to San Ramon Valley which is characterized by gently rolling hills. The San Ramon Valley Regional Medical Center, which opened in 1990, is located to the north and an existing church is located to the southwest. There are also private residences located to the southeast. The site is shown in Figure 1. Numerous faults run close to the site, the most significant of which are the Calaveras and Pleasanton faults. The site has also had a long history of slope instability and has been the subject of numerous investigations. Studies conducted in 1979 and 1984 concluded that there was a landslide in the area and recommended that a buttress shear key be constructed between the subject site and the existing church for a sewer main as well as removal and replacement of the head area of the old landslide to stabilize the hospital site. While two previous geotechnical studies in 2008 and 2016 identified slope instability, they did not recognize the genesis and limits of the old landslide on the western portion of the site or the limits of the active landslide on the eastern portion of the site.

Jan 1, 2018

By Richard J. Finno

Detailed measurements made at a test section adjacent to a deep braced cut and other published data are combined to illustrate the limitations of the common methods of predicting movements associated with excavations in soft to medium clay. While past performance data can be used to estimate expected responses before construction in many cases, actual wall and soil deformations throughout construction can only be estimated using finite element procedures. Success of such analyses depends equally upon considering all aspects of construction that induce strains in adjacent soil, such as wall installation, excavation and bracing sequence, and time, and adequately modeling soil stress-strain behavior. Even when these two criteria are met, soil deformations can not be predicted adequately when strain levels exceed those that produce peak shear stress.

Jan 1, 1991

By S. X. Liang

In China, the bearing capacity predictions of the pile with Stress-Wave Theory have been developed rapidly in recent years. This paper recommended a DZH-3 Pile Driving Analyzer and its relevant computer programs. Taking Qinghai Hotel Project for example, it gave their applications in the dynamic tests of large diameter cast-in-place piles.

Jan 1, 2010

By WenJun Dong

This paper presents the stability assessment of the steel pipe piles that are used to support a deadman beam to anchor an adjacent bulkhead wall. Finite element analyses are performed to assess the stability of the bulkhead wall and determine the required tie-back force to the pile. The piles are relatively close to the bulkhead wall such that their soil resistance wedge zones are not fully developed but truncated by the bulkhead wall. The reduced lateral resistance capacity of the anchor piles is determined by applying the Coulomb wedge method on the truncated soil passive zones between the pile and wall. Both the conventional soldier pile stability (in terms of force and moment equilibrium) and Winkler soil spring (for soil-pile-interaction) analyses are used to assess the stability of the anchor piles.

Sep 8, 2021

By Flor De Cock

The paper reflects part of the work from the European Regional Technical Committee on Piles (ERTC3) during its mandate between 1994 and 1999, and, in particular, describes the find­ings from an International Seminar held in 1997 in Brussels on European practice for design­ing axially loaded piles. The seminar included contributions from 17 European countries, each of which provided a synopsis of their respective national design approaches. This paper pays particular attention to the design methods based on laboratory and in-situ test data for both bored and displacement piles.

Jan 1, 2002

By William S. Heckman

a. When to use: high surcharges, vertical capacity required, limit noise and eliminate vibrations, low headroom, eliminate vibration induced settlements. b. Advantages: eliminates impact noise and vibrations, high section modulus if required, vertical load bearing capacity; corrosion resistant, easy to apply facing for use as a permanent wall, adapts to complex wall layouts, would allow top- down construction, very high uplift resistance. c. Disadvantages: spoil disposal, not water tight, cannot penetrate rock and most obstructions, soil can erode between the piles if surface water and ground water are not controlled, hard to install reinforcing beams over 409 long; subject to high negative skin friction loads, high grout takes in rubble and organic soils. e. Relative cost to other systems: 30% to 50% more expensive than driven soldier piles and lagging except when surcharge loads are involved, or the pile cannot be driven due to noise and vibrations. About the same cost as a sheet pile system. Very competitive if high vertical load must be supported by the wall.

Jan 1, 1997

Jan 1, 1997

By M. Pernot

A 12 m-deep excavation has to be perfomed in the Shanghai soft clay to install an underground electric substation. This article was originally intended to study the behaviour of the wall, the excavation bottom and the surrounding ground during the excavation. Since the works are behind schedule, and the data referring to the excavations are not, therefore, available, the article is limited to a presentation of the analysis methods that we envisaged for the study of the behaviour of the excavation.

Jan 1, 2010

By M. England

A method for the analysis and prediction of single pile displacement behaviour is described. It is the displacement in time, under constant load, based on the use of hyperbolic functions to characterise individual constituents of the displacement-time behaviour. Extensive use of this technique has confirmed its validity in a variety of soils and that consolidation and creep settlement appear to be indistinguishable. The algorithms employed are suitable to model the displacement behaviour from the onset of load to infinite time for all types of piles and surface foundations. Until the advent of computer controlled static load testing, analysis of the displacement-time characteristic during pile load tests has been hindered by the quality of the data recorded and inconsistency of loading. This has hitherto made the development of suitable behavioural models very difficult. Understanding the soil deformation within a proper time framework allows the subject of pile instrumentation and testing to be developed. The equipment required is basically a computer controlled loading and pile head displacement measuring system which allows accurate analysis of the settlement characteristic in almost every situation.

Jan 1, 1993

? Hollow Stem Auger ? Drill Bits ? Leads/Torque Arm ? Hydraulic Gearbox ? Hydraulic Power Unit ? Grout Pump ? Crawler Crane

Jan 1, 2000

By Allan Herse

"The years following World War II were nation building years in Australia. Soldiers returned from the European and Asian theatres of war sparking a major infrastructure construction boom. Dams and highways were built to keep up with the growth of towns and cities, which were bursting at the seams, not just from the returning soldiers settling down with their families but also from the many waves of refugees from war torn areas around the globe.The demand for electricity generation and distribution required for the growing population sparked the expansion of the national power grid with new high-voltage transmission towers appearing across the landscape. However, with an original design life of 50 years, those transmission lines constructed in the 1950s are nearing, or are at the end of, their anticipated service life.In recent years, the Australian power distribution network has changed from a period of high construction activity in greenfield high-voltage lines to a period that is now focused on reducing cost and maintaining existing assets. Replacing aboveground structural members and electrical components is relatively simple even under live conditions. However, the replacement or repair of tower foundations, many of which are in remote locations, has been a problem that has caused difficulties for power utilities trying to operate on a budget while also avoiding costly and unpopular power outages.With thousands of miles of aging transmission lines needing life extension work, Piling & Civil Australia (PCA) has developed a patented system of upgrading the foundations with micropiles while under live-line conditions without requiring costly outages. The system is seen as revolutionary by power utilities, allowing the utilities to extend the life of their existing assets until demand increases to warrant the construction of a new line. PCA has been working on a potential solution with Powerlink Queensland for the past 5 years to develop a quick and cost-effective foundation replacement system that can extend the life of its existing asset base anywhere from an additional 5 years to 50 years.With design support from Quanta Subsurface, USA, PCA recently completed the foundation replacement of 26 lattice tower foundations in the Townsville region of North Queensland. Using a steel bracket (patent pending) to connect hollow bar micropiles to the lattice towers, the installation techniques that were developed enabled the micropiles to be installed within a tolerance of less than about 3/8 in (10 mm) through the existing steel grillage foundation while maintaining live line conditions. The project was an Australian first and a trial by Powerlink for wider use within its network, and it was delivered on time and within budget at one tenth of the cost of traditional methods."

Jan 1, 2017

By Allan Herse

"The years following World War II were nation building years in Australia. Soldiers returned from the European and Asian theatres of war sparking a major infrastructure construction boom. Dams and highways were built to keep up with the growth of towns and cities, which were bursting at the seams, not just from the returning soldiers settling down with their families but also from the many waves of refugees from war torn areas around the globe.The demand for electricity generation and distribution required for the growing population sparked the expansion of the national power grid with new high-voltage transmission towers appearing across the landscape. However, with an original design life of 50 years, those transmission lines constructed in the 1950s are nearing, or are at the end of, their anticipated service life.In recent years, the Australian power distribution network has changed from a period of high construction activity in greenfield high-voltage lines to a period that is now focused on reducing cost and maintaining existing assets. Replacing aboveground structural members and electrical components is relatively simple even under live conditions. However, the replacement or repair of tower foundations, many of which are in remote locations, has been a problem that has caused difficulties for power utilities trying to operate on a budget while also avoiding costly and unpopular power outages. With thousands of miles of aging transmission lines needing life extension work, Piling & Civil Australia (PCA) has developed a patented system of upgrading the foundations with micropiles while under live-line conditions without requiring costly outages. The system is seen as revolutionary by power utilities, allowing the utilities to extend the life of their existing assets until demand increases to warrant the construction of a new line. PCA has been working on a potential solution with Powerlink Queensland for the past 5 years to develop a quick and cost-effective foundation replacement system that can extend the life of its existing asset base anywhere from an additional 5 years to 50 years.With design support from Quanta Subsurface, USA, PCA recently completed the foundation replacement of 26 lattice tower foundations in the Townsville region of North Queensland. Using a steel bracket (patent pending) to connect hollow bar micropiles to the lattice towers, the installation techniques that were developed enabled the micropiles to be installed within a tolerance of less than about 3/8 in (10 mm) through the existing steel grillage foundation while maintaining live line conditions. The project was an Australian first and a trial by Powerlink for wider use within its network, and it was delivered on time and within budget at one tenth of the cost of traditional methods."

Jan 1, 2017

Port Gaspé is located on the back side of Gaspé bay and is protected by a natural sand barrier with a length of 2,5 km, from which it got its name, Gaspé Sandy Beach (1). Since 1904 the Gaspé region had a deep water wharf, initially very different, in fact, from the one existing just before the recent reconstruction (2). This wharf with a length of 228 m and a width of 23 m was build of timber cribs. The outside walls of these cribs had been doubled with a wooden wall, creosote impregnated to provide resistance to decay and to the attack of marine organisms (limnorias) (3). Fifteen years ago the upper part of the wood construction had to be removed, because of progressing rottenness and was replaced by an L-shaped reinforced concrete structure (4).

Jan 1, 1987

By Mario Terceros H, Bengt H. Fellenius

"ABSTRACTThe city of Santa Cruz, Bolivia, is historically dominated by houses and three to five storey buildings.The geology in and around the city is such that even very light buildings need to be supported onpiles. The recent increase of the Bolivian economy, notably that of Santa Cruz, has created a demandfor new residential as well as office and industrial buildings, which mostly consist of multi-storey orhigh-rise buildings with significantly larger foundation loads. Foundation piles have become largerand longer, and the load on individual piles is increased. The development has resulted in an increasein the demand for more sophisticated design and construction methods and stricter approach toverifying the quality of the construction processes and results.This paper describes to geology of the Santa Cruz region and how the geotechnical conditions areconsidered in the design and construction of piled foundations. The improvement of past constructionand design techniques, based mostly on bored piles constructed with bentonite slurry, is beingreplaced with new methods of constructing bored piles, e.g. the Full Displacement Pile (FDP) andincorporation of techniques such as enlarging the pile toe, e.g., with the Expander Body. This paperpresents the results of several full-scale tests and discusses the incorporation of the test results indesign and construction.1 GEOLOGY OF THE REGIONSanta Cruz de la Sierra is located in the eastern lowlands and sub-Andean zone of Bolivia, SouthAmerica. The area lies at an elevation of about +400 m and the geology is a Paleozoic (250 millionyears old) sedimentary basin. The soils of interest to civil engineering construction are quaternarywith the dominant minerals being calcite, silica and feldspar. The main agent is the Piray River and itstributaries. Their past meandering over the area has resulted in a sedimentation-erosionsedimentationprocess and a profile dominated by fine to medium sands with intermittent layers ofclay or clayey sand. With increasing distance from the river, the clay-containing layers are thicker.Fig.1.- View of Bolivia with location of Santa Cruz and map of Santa CruzThe upper about 15 to 18 m thick part of the profile consists of normally consolidated layers of clays,silts, sands, in various combination and thickness. Below, the soil is more homogeneous and consistsmostly of sand and gravel. The groundwater table lies typically at a depth of about 6 m in the highestpart of the city and at about 1 to 3 m depth in the lowest part of the city."

Jan 1, 2014

By D. Waite

The Chairman opened the session by wondering why so few papers on Maritime Structures had been received for this conference. Perhaps because the marine environment is so hostile and the access so difficult that engineers tend to be more prudent about new ideas and designs. Dennis Waite noted the number of grey hairs in the room - grey hairs which could be equated with experience gained the hard way. He hoped that this experience would be passed on in the discussion period of this session. The Chairman was delighted to welcome two authors from China, Mr Sun and Mr Liang. He was most grateful on behalf of the conference for their efforts both in preparing their papers and for being able to present them. He regretted that Messrs Noce and Fedolino were not able to present their paper and then welcomed Mr Christensen from Denmark who would present the first paper.

Jan 1, 1991

By Sanjeev Malhotra

"This paper presents the results of a pile installation monitoring and performance assessment program for pile foundations supporting 14 piers and 2 abutments of the 1700-ft long bridge crossing over a river in Baltimore, Maryland. Dynamic measurements were conducted during installation and restrike of 16 test piles, one at each support location. The foundation piles were 30-inch diameter, 0.75 inch thick pipe piles at the piers and 24-inch diameter, 0.5 inch thick at the abutments. The piles at the piers were approximately 100 ft long and were designed to carry 260 kips service load with a factor of safety of 2.25. The piles were driven open ended into a variable site stratigraphy containing recent deposits of organic clayey silts near the mudline followed by loose to medium dense sand, with some silt, and then by soil deposits from the Cretaceous period consisting primarily of dense to very dense, poorly to well graded sands and gravels and cobbles, with occasional seams of very hard to very stiff, low to moderate plasticity silts and clays. This paper presents the approach taken to evaluate the driven index piles and to develop criteria for driving production piles. It provides the Engineer with some data on pile driveability in Cretaceous soils in the Baltimore area, soil set-up effect, and an estimate of pile capacity.INTRODUCTIONThe typical approach to pile foundation design and construction should include an indicator pile program with dynamic measurements and a static load test program. However very often paucity of funds and schedule constraints cause an owner to do away with conventional static load testing which can take $25,000 to $100,000 and several weeks per test. This paper examines an alternate (though not equivalent) truncated approach to foundation assessment and presents a case history where this approach was implemented.Dynamic measurements were conducted during pile installation for the 14 piers and 2 abutments of the new 1700-ft long bridge over a river in Baltimore, Maryland. Strain transducers and accelerometers were attached to the pile top during initial driving and restrike of 16 pipe piles. The foundation piles consisted of 30-inch outside diameter, 0.75-inch thick pipe piles at the piers and 24-inch outside diameter, 0.5 inch thick at the abutments. The piles were driven open ended into a variable site stratigraphy. The approach taken to assess the foundation performance included 1) a pre-field wave equation driveability analyses, 2) field pile driving measurements, 3) post-field Case Pile Wave Equation Analyses (CAPWAP), and, 4) revised wave equation analyses based on field and CAPWAP data. The following sections describe in greater detail each of the steps taken to assess foundation performance and the results obtained."

Jan 1, 2005

By David R. Beadman

The Fleming method is widely used for the analysis and prediction of single pile behaviour under maintained loading. The method does not distinguish between bored and driven piles. Driven piling avoids the need to dispose of spoil from the pile installation and is therefore becoming increasingly attractive. This paper considers the theoretical effects of the possible preload at the base of a driven pile after installation, using the hyperbolic functions as defined by Fleming. The Fleming method is reviewed and the equations and analyses are adapted, using spreadsheets, to allow for a possible preload. The simplifying assumption of the effect of the elastic compression of the pile is also reviewed and a more analytical method adopted to assess the elastic compression. Some driven pile test data is analysed to consider the possible effects of the preload on the performance of a driven pile and to test the theoretical relationships that are developed in the paper.

Jan 1, 2006

By P. Kiruthika, A. Murali Krishna

Soil liquefaction is a dangerous phenomenon that involves huge damages during strong earthquake ground motion event. Stone columns (SCs) are widely used as liquefaction mitigation element which is expected to perform the improvements against liquefaction hazard by densifying, increasing the stiffness and rapid dissipation of excess pore water pressure in the surrounding soil. Although in the recent times few studies on the behaviour of stone columns in the seismic zone has evolved, the performance of SCs in the multi-layered soils is not extensively examined. This paper presents the numerical investigations on the performance of SCs installed in the multi-layered soils as a liquefaction mitigation measure against the seismic loading. The acceleration time histories, Excess Porewater Pressure (EPP), vertical displacement and stress ratio evaluated along different depths using PLAXIS 2D. With the installation of stone column there is a considerable reduction in the acceleration amplitude, which in turn reduces the EPP and vertical displacement at different locations and the amplitude of reduction depends on the soil stiffness levels at the depth.

Sep 1, 2022

By Reda Mikhail, M. Birkan Bayrak

The Washington State Department of Transportation (WSDOT) State Route (SR) 167/70th Avenue East Vicinity Bridge Replacement Design-Build project is located in Fife, Washington. This $40 million project consists of replacing the existing 70th Avenue Bridge over Interstate 5 (I-5) with a single-span bridge of about 220 feet long with approach embankments. The subsurface conditions along the new bridge alignment generally consists of alluvial deposits with high potential of liquefaction overlying glacially overridden deposits. In the early stages of the project, drilled shafts were considered as the deep foundation system; however, after an additional subsurface investigation is completed at the site, driven pipe piles were selected as the deep foundation system. Bridge abutments are supported by 24-inch diameter, 80-foot-long open-end driven steel pipe piles. The pile length was determined to bypass a relatively thick liquefiable zone and to tip the piles above what could be compressible soils. The use of advanced seismic analysis was instrumental in optimizing the pile length. The dynamic testing performed on numerous piles indicated what could be unique soil setup factors compared to those measured in local projects as well as those reported in national design manuals. Detailed discussions of the pile foundations design and construction is presented in this paper.

Sep 8, 2021

By Reda M. Bakeer

"An approach slab is the roadway segment that immediately follows a bridge intended to provide a smooth transition between the two elements. Some approach slabs have developed rough rideability with time due to differential settlement between the roadway embankment and the bridge. Soils in south Louisiana are generally poor and highly compressible and, therefore, pile-supported approach slabs were occasionally used. Timber piles of variable lengths are driven into the soft soils where no appreciable toe support exists. This resulted in the soils both supporting loads through shaft resistance and yet experiencing long-term consolidation settlement. Field testing and review of the records of over 120 approach slabs constructed in south Louisiana yielded the conclusion that their performance is primarily governed by negative skin friction (downdrag) imposed on the relatively short timber piles. A software (TU-DRAG) was developed to evaluate the deflection profile of a pile-supported approach slab based on its geometry and conditions of the underlying soils. It evaluates the effect of dragload considering the number and spacing of the piles at each transverse row and their variable lengths along the approach slab. TU-DRAG was utilized in the design of two transportation related projects which have been in service for more than 10 years.INTRODUCTIONThe problem of differential settlement at bridge approaches or “the bump at the bridge” has been recognized for many years. Research studies (1986, 1989, 1997, 2009 and 2013) by the Transportation Research Board (TRB) and the Federal Highway Administration (FHWA) provided comprehensive evaluations of the performance of bridge approach slabs by assessing their field conditions and construction and maintenance records. Various states have also performed their own studies to investigate the performance of bridge approach slabs. The studies considered various types of structures including soil- and pile-supported approach slabs, integral bridge abutments and open-end abutments. Recommendations were provided for the design of new structures and for maintaining and repairing existing structures. Guidelines were offered regarding tolerable movements of bridges and their foundations based on measurements of vertical and horizontal movements of 580 bridges Moulton (1986). Vertical and horizontal movements greater than 102 mm (4 inches) and 51 mm (2 inches), respectively, were considered intolerable. Tolerable limits for angular distortion (differential settlement to span length) were suggested to be 1/250 and 1/200 for continuous and simple spans, respectively. It was reported that a differential settlement greater than 13 mm (0.5 inch) at the bridge interface would be sufficient to constitute a “bump” requiring mitigation."

Jan 1, 2017