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By Lok M. Sharma

"Construction of a new bridge in a seismically sensitive area requires careful assessment of earthquake impact on the serviceability of the facility. Not only is the superstructure vulnerable, the foundations play a key role in the bridge’s survivability. A new bridge in eastern part of the state of Missouri in the U.S.A. is located in a seismically active area and hence subject to additional thrust on the foundations and superstructure and potential damage due to liquefaction. An eleven span bridge with foundation soils varying from shallow bedrock to over 30 m (100 feet) overburden soils were considered for the bridge support piers. Two of the bridge support bents located within the flood plain area through over 30m (100 feet) of alluvial deposits were considered most affected by an earthquake event due to the additional thrust and lateral ground spreading. This paper describes the determination of site specific seismic hazard, numerical modelling of the foundation system, and methodology of dynamic analyses, effects of lateral spreading and liquefaction potential on bridge support bents. From numerical modelling using FLAC, the increase in thrust on piers and deformations were computed to predict the behavior of the foundations.INTRODUCTIONA newly constructed bridge on route US 40 crosses the Missouri River west of St. Louis, Missouri and upstream of Mississippi River in mid-west USA. The west abutment area has near surface bedrock while the east abutment area has overburden deposits over 30m (100 feet) thick, mostly river sediments comprising of silts, lean clays and sands overlying bedrock. Softer layers of silts and sands in the east river bank area are assessed to be liquefiable during a high magnitude earthquake event. St Louis area has a potential for a high magnitude earthquake due to the New Madrid Fault some 160km (100 miles) south. The bridge foundations were designed as drilled piers, 2 m (8 feet) in diameter and socketed into the bedrock. Bents No. 10 and 11, located in the lower flood plain area of the river, are considered to be most affected by a seismic event.In order to perform dynamic analyses of the foundations, earthquake ground motion time history was developed for the specific site using a Probabilistic Seismic Hazard Analysis (PSHA) and selecting and scaling of a recorded time history. Relying on the U.S. Geological Survey (USGS) Earthquake Hazard Program for the PSHA and AASHTO Guide Specifications for LRFD Seismic Bridge Design, spectral acceleration values for the site were developed. The spectral acceleration values were for a 7 percent probability of exceedance in 75 years (1000 year return). Numerical modelling using FLAC computer program was performed. This paper presents the seismic design parameters, methodology used in the dynamic analyses, static and dynamic analyses, impact and mitigation of liquefaction on Bents 10 and 11 and the abutment fills, and effect of lateral spreading on the foundations in the lower flood plain area of the bridge. From the numerical modelling, increase in thrusts on pier foundations and estimated deformation were computed."

Jan 1, 2017

By Martin D. Larisch

The construction of diaphragm walls and most large-diameter bored piles (piers) is often carried out under drilling support fluids to temporarily stabilise the excavation prior to concrete placement. In most cases such fluids are either mineral-based slurries (bentonite) or polymer support fluids. The working mechanisms of these two fluid types are fundamentally different. Designers need to consider possible fluid-related impacts on the permanent design performance of the project-specific deep foundations as well as for the temporary excavation stage during construction. Robust design methods for bentonite slurry-supported excavations have been developed in the last few decades and the working principles and associated risks of such mineral-based slurries are understood reasonably well. However, such meth-ods have not been developed in detail for polymer-based drilling fluids. This document provides a brief overview of the main characteristics of bentonite- and polymer-based drilling fluids as a guide for construction practitioners and design engineers alike. The paper also high-lights some common construction risks related to casing installation and the selection of suitable fluid systems for different ground conditions. Typical defects caused by the incorrect application of drilling support fluids, and their pro-active mitigation, are discussed, too. In addition, the basic concepts of sta-bility calculations for bentonite fluid-supported deep excavations are briefly introduced and their ap-plicability for other fluid types such as polymer-based support fluids or water are reviewed.

Nov 1, 2022

By Takefumi Takuma, Masashi Nagano, Christopher DellAringa

Multiple agencies in Southern California are retrofitting and upgrading their levees to catch up with ever-advancing urbanization affecting the requirements for existing channels and levees in this seismically active zone. Pressed-in sheet piles have been specified on some of these projects to minimize noise and vibration problems associated with sheet pile installation. This paper will study three Southern California levee and sewer pipeline retrofit projects that utilized pressed-in sheet piles in hard soil conditions with N-values higher than 50. BACKGROUND Southern California is home to numerous drainage channels fortified with earthen levees. In spite of the region’s semi-arid climate with varying annual precipitation from year to year, winter storms can bring in heavy and continuous rainfall to the area which overwhelms the levees’ capacities at times. Some levees are running through densely populated areas with homes and other sensitive structures such as underground utilities and bridge piers. Conventional sheet pile driving utilizes either percussive or vibratory pile driving methods, both of which generate high levels of noise and vibration, causing nuisance and potential damage to nearby structures. On the other hand, the press-in piling method utilizes a hydraulic force to push piles into the ground, thus practically eliminating the noise and vibration issue. Although there are types of press-in piling systems mounted on tall leaders on large crawler-base machines, they are less frequently used due to its much larger size and more limited drivability than the type discussed hereunder. The other type of press-in machine sits on top of already installed piles and is anchored with its own weight and additional counter weight when starting off as shown in Figure 1. Once the first few piles are pressed in, the equipment grips on top of the installed piles and moves forward on its own as the pile installation progresses. See Figure 2. This method does not use a vibratory or percussive force to install piles.

Jan 1, 2018

By Patrick K. Wong, Richard Kelly

"The variability in strength and compressibility of in situ deep soil mixing products can be greater than the variability of the natural soil. However, satisfactory performance can be achieved by careful construction and an appropriate QA/QC program. This paper presents a case study on the use of deep dry soil mixing columns to support several embankments over soft clay along a highway project. Post-construction settlement monitoring indicated that good performance is achieved where the acceptance criteria are met, except in an area with high organic content. Embankments with contrasting performance are compared to the quality control test results which comprised laboratory testing of core samples as well as in situ test results such as pull-out and push-in vanes and conventional cone penetration tests. Drawing on the performance results and quality control testing, discussions and guidelines are given on quality assurance acceptance criteria and construction control testing regime for future projects.INTRODUCTIONBetween 2008 and 2012, the largest deep dry soil mixing (DSM) contract during that time in the southern hemisphere was carried out for the Ballina Bypass project. The project, comprising 12 km upgrade of the Pacific Highway located in northern New South Wales close to the border of Queensland, was commissioned by the Roads and Maritime Services (RMS) of NSW. The ground improvement contractor was Keller Ground Engineering (KGE) Australia. Seven different types of ground improvement techniques were employed for the project, ranging from low embankment strategy with nominal preloading, to surcharge with wick drains, light weight bottom ash fill, DSM, vibro-replacement stone columns, dynamic replacement, and vacuum consolidation (installed by Menard Bachy Pty Ltd). Different techniques were chosen depending on time program, cost, and performance requirements relative to proximity to piled structures (e.g. bridge abutments) and post-construction settlement and differential settlement for either rigid or flexible pavements at different locations.DSM was the most utilized ground improvement technique employed on the project, comprising a total of about 285 km of 0.8 m diameter columns to depths up to 18 m for the purpose of supporting bridge approach embankments and culverts with embankment heights up to 6 m. DSM was chosen due to the very soft nature of the clay soil with moisture content practically at liquid limit, and the relative speed and economy of the system. Dry cement powder at rates of 160 kg/m3 to 200 kg/m3 were pneumatically discharged via the hollow stem of the mixing tool, and mixed with the soil (using multiple horizontally mounted paddles on a single vertical stem) at high speed as the mixing tool is withdrawn."

Jan 1, 2015

By Michael A. Knott

Large lateral forces on bridge foundations due to extreme events such as vessel collisions, earthquakes, and wave forces on storm surges during hurricane events are often the controlling design condition for bridge foundations. A review of the American Association of State Highway and Transportation Officials (AASHTO) vessel collision analysis and design codes used in the United States for highway bridges will be presented. The paper includes the background and development of the AASHTO Guide Specification and Commentary for Vessel Collision Design of Highway Bridges (1991) and vessel collision provisions of the AASHTO LRFD Bridge Design Specifications (3rd Edition 2004 and the approved 2005 Interims). Experience in using the AASHTO codes will be discussed and observations on the adequacy and gaps, comparison with the European Standard Code, and recommendations for immediate and long term needs will be presented.

Jan 1, 2013

By Howard A. Perko, M. Mae Benvenga, Heather H. Trantham

Displacement of soil and groundwater during helical pile installation can produce excess pore water pressures (PWP) in fine-grained soils. Pore water pressure reduces effective stress in the soil immediately adjacent to the helical pile shaft and near the helical piles. Previous studies have shown generation of PWP may affect the capacity to torque ratios of the helical bearing elements. Large diameter helical piles that generate much of their torque and capacity from shaft adhesion are affected by PWP and therefore exhibit significant pile "freeze" after installation. Computer modeling is used herein to evaluate PWP immediately adjacent to helical pile shafts during installation in various soil types. The models show the degree and distance from the shaft that is influenced by PWP during installation and the amount of time required for the PWP to dissipate. Pile freeze has been measured on several project sites by re‐torque measurements. These re-torque data are compared with computer modeling and correlations between saturated hydraulic conductivity and dissipation time are presented and discussed. INTRODUCTION Helical piles are full-displacement piles, meaning installation does not produce drill spoil. Soil is displaced laterally as the pile progresses into the ground. This displacement of soil causes an increase in PWP, which reduces adhesion between the pile and the soil. For helical piles with small-diameter shafts, adhesion contributes little to the overall capacity and torque of the pile, so PWP changes are not typically considered in determining pile capacity. In modern construction, the use of larger diameter helical piles has become very common. For large-diameter helical piles, changes in PWP immediately adjacent the shaft can be quite large during installation. Increased pore water pressure and reduced adhesion can have a temporary effect on pile capacity and installation torque.

Jan 1, 2018

By David L. Borusiewicz, M. Suri Surendra

"Abstract Helical piles have been used as anchors and for supporting lightly loaded structures as a method of underpinning, etc in the past. Recently, helical piles are being used to support new structures because of their simple installation process using relatively light and mobile equipment. This paper presents the results of evaluation and design performed for the temporary support of existing piers during a bridge rehabilitation project.INTRODUCTIONThe helical screw foundation was invented and patented by Alexander Mitchell in England in 1833. He installed screw piles to support lighthouses in the tidal basins of England. Many applications in the earlier years in the USA were in North Carolina and in Florida to support lighthouses (in coastal plain deposits). A lighthouse of similar foundation design is still in use at Key Biscayne, Florida.In the USA, the helical piles were reintroduced as foundation elements for electrical transmission towers. Helical piles were also used for anchoring guys of self supported towers and as tie-backs for excavation support systems. Typically, helical piles are being used for supporting lightly loaded buildings and for underpinning buildings undergoing distress as a means of remediation. The helical piles are not commonly used in the transportation industry.HELICAL PILESHelical pile is a segmented deep foundation system with helical bearing plates welded to a central steel shaft. Load is transferred from the shaft to the soil through these bearing plates. Central steel shafts are available in either a square shaft (Type SS) or a round shaft (Type RS). The Type SS series are available in 38 mm to 57 mm square sizes. The Type RS series are available in 73 mm to 114 mm diameter sizes. Type SS-RS combinations are also available for compression applications in soil conditions where dense/hard soils must be penetrated with softer/loose soils above the bearing strata.The leading segment consists of a shaft with one or more helical plates that are welded to the shaft. The plates vary in diameter from 203 mm to 355.5 mm and have a thickness of 9.5 mm or 13.7 mm. Typically the plate diameter increases from the bottom of the shaft upward. A helical bearing plate or helix is one pitch of a screw thread. All helices, regardless of their diameter, have a standard 76 mm pitch. Being a true helical shape, the helices do not auger into the soil but rather screw into it with minimal soil disturbance. Helical plates are generally spaced a distance of two to three times the diameter of the plate directly below in order for them to function independently as individual bearing elements. A typical detail of helical pile is shown on Figure 1."

Jan 1, 2014

By Ali S. Fayad

"In June 2014, Orange County Flood Control District (OCFCD) completed construction improvements of the East Garden Grove-Wintersburg Channel for a price of $42 million. Instead of the pre-existing traditional trapezoidal levee, the channel was improved with a vertical compact levee. Dubbed Soil-Mix-Sandwich (SMS), this geo-structural and environmental solution for coastal channel improvements, underlain by liquefiable soil strata, was both a design and construction innovation. It employed Deep Soil Cement Mixing (DSCM) within the confines of a hydraulically-pressed (Giken Method) sheet pile duo. SMS was unique because it incorporated both subterranean and supra-dredge-line soil mixing within a very narrow workspace. Its DSCM pattern aimed at optimum densification of the workspace and was confirmed during the construction process. It availed the DSCM sub-contractor (Hayward Baker Inc.) the opportunity to demonstrate the fitness of their huge wet-mixing machinery within a very confined access-area and introduced approximately 70,000 cubic yards of DSCM within a limited 15 foot workspace width that stretched for a mile. The sheet pile duo created a construction-enclosure that became a stay-in-place load resisting system. PROJECT CHRONOLOGY AND LOCATIONAn Orange County Flood Control District (OCFCD) project-report was commissioned to study the East Garden Grove Wintersburg channel (OCFCD facility # C05). The report examined the hydraulic conveyance of the C05 channel and was concluded in 1994 by Williamson & Schmidt. The project-report did not encompass extensive geologic studies; but it provided several alternatives for channel improvement. It recommended a single row of sheet piles as the preferred alternative for the downstream reach.The most downstream reach of the C05 channel is located in an environmentally sensitive area, in City of Huntington Beach, California, USA. Its site includes seismic chasms that surface within the C05-footprint (the Newport- Inglewood tectonic fault). Extensive deposits of liquefiable soil exist beneath the channel. Furthermore, tidal-influence prevails against the channel levee. Implementation of a successful design for channel improvement emerged after several traditional concepts were deemed unacceptable by geotechnical consultants. OC Public Works (on behalf of OCFCD) was in need of a design and construction technique that mitigated many associated risks. From these circumstances, Soil-Mix-Sandwich was born and was referred to in the rest of this discussion as SMS. OC Public Works required the SMS design concept to undergo verification by independent geotechnical consultants. SMS chronology from conception to construction can be summarized as follows:"

Jan 1, 2015

By Kouichi Tomisawa

Two bridges were constructed for extension work of Central Hokkaido Connection Road in 2005 at two different sites. Pile group foundations were employed for the foundations of abutments of the two bridges. In order to assess the performance of the constructed piles in the sites and to obtain design parameters for design in future, static alternating cyclic horizontal load test was carried out on one of the open-ended steel pipe piles constructed at each site. The ground at one site was characterised as a thick deposit of volcanic soils, and the ground at the other site was characterised as a very soft peat layer near the surface. In this paper the results of static alternating cyclic horizontal load tests on the piles at the two sites are presented and discussed in detail.

Jan 1, 2006

By Edwin W. Meyer

The augered cast-in-place piling technique was used to install deep foundations 20 feet into weathered sandstone. The project involved the upgrading of the Air Quality Control System (AQCS) for a 560 megawatt coal fired power plant located in Stillwater, Minnesota. The site subsurface consisted of 20 feet of overburden overlying weak sandstone. The overburden consisted of sands and gravels with cobbles and boulders, and variable thicknesses of peat. Ground-water at the site was approximately 8 feet deep. Two foot diameter piers were selected to facilitate installation through the cobbles and boulders in the over-burden and to penetrate the sandstone 22 feet. During installation of the first pier, the weak sandstone broke down to sand-sized material that could not be cleaned from the pier hole without the use of slurry to hold the material in suspension. However, the use of slurry would significantly impact both schedule and cost. Since the sandstone could be easily drilled with the pier equipment, it was believed that 2 foot diameter deep foundations could be installed as designed using augered cast-in-place piling techniques. A brief test drilling pro-gram was conducted to evaluate the viability of 2 foot diameter continuous flight augers penetrating 22 feet into the weak sandstone. The test drilling indicated that augered cast-in-place installation techniques should be successful. Following a short delay to mobilize the additional required equipment, construction commenced. Installation of the 2 foot diameter augered cast-in-place piling to a depth of 22 feet into the weak sandstone was successfully performed.

Jan 1, 2006

By Alexander Blatt, Franz-Werner Gerressen

Power Point Presetation at DFI 2022

Sep 1, 2022

By Dennis W. Boehm

The building boom of the late 1970's and early 1980's has all but used up most of the better sites across the more populated metropolitan areas of the United States. This means that current buildings and other types of structures are being founded on more marginal sites. The use of marginal sites has placed ever-increasing quality control on the installation of the deep foundation systems utilized for these sites. Several remedial techniques are available for the repair of the deep foundation systems. These include minipiles, compaction grouting and jet grouting. Eight case histories are cited where these methods have been utilized to repair deep foundations.

Jan 1, 1999

By Patrick Bermingham

The advancement of hydraulic impact hammers has followed the general advancement of hydraulics. The construction industry has been revolutionized by the application of hydraulics in excavators, cranes and, of course, in the hydraulic vibratory driver/extractor, which has become a standard tool. The innate ability to move a large mass with a very small displaced volume has given hydraulic power the advantage over previous power mediums. Recent development of more specialized and complex seal configurations and compounds has greatly improved the reliability and permitted the use of higher pressures in hydraulic systems.

Jan 1, 1987

By Venkatesh S. V J, Shubha M, Srilakshmi G

Choosing for the best option of pile foundations to overcome large lateral and uplift loads for the foundations in transmission line towers/offshore environment is still being a concern to achieve the required capacities but also by considering the suitability aspect in the environment. The objective of this paper is to review the methods that have been done for knowing the uplift resistance and lateral resistance of pedestal piles. Investigations by different methods such as experimental studies, numerical and analytical studies have been done by various researchers in order to evaluate the response of a belled pile. These methods are discussed in this paper and the comparison with straight shaft pile based upon the test and analysis. The results indicated that the uplift resistance and lateral resistance were significantly increased with the adoption of belled piles than straight shaft piles.

Sep 1, 2022

By D. E. Sherwood

Recent developments in high torque hydraulic rotary rigs has lead to the construction of secant bored pile walls by rotary drilling methods in circumstances where earlier methods were difficult and in some cases impossible. The evolution of secant bored pile wall construction is described including classical, rotary drilled and continuous flight auger construction methods. The paper then details the restraints which have been created in recent inner city redevelopment, many of which were not relevant in the early days of the technique. Typical examples of walls are presented to show the adapatability and advantages of the secant bored pile wall method. A number of in-situ retaining wall construction techniques are then compared in detail with regard to relative cost, technical quality and practicality.

Jan 1, 1989

By Peter J. Nicholson

The methods of reinforcement to be discussed in this paper are all insitu methods, ones that can be used on the soil structure as it exists in the ground, and do not rely on excavation and replacement of the soil. Current practice in the United States, as well as new ideas and methods, will be discussed as they relate to slope stability, retaining walls, and to other uses such as control of mine or cavity related subsidence and to liquefaction control under existing structures. The method is based on the concept of "nailing" or reinforcing the soil in place, and thereby causing a mass of soil to act as a coherent unit. When performed properly, a true gravity structure can be constructed, one that will remain intact under both horizontal and vertical loadings and that will also resist vibrational and seismic loadings.

Jan 1, 1991

By Wolf-R. Under

For improvement of urban traffic infrastructure, the City of Amsterdam is cur­rently constructing the 9.5 km long North-South Metro line passing through the central districts of Amsterdam. Focal section of the project is the Central Station linking the NS Line with the Central Railway Station, the East Metro line, new bus and tramway terminals, ferries and individual traffic. Construction works required for the project are of high complexity and technical standards. They are executed under severe restrictions concerning programming, space, logistics, and impact on the integrity of existing buildings and structures as all existing installations and facilities have to maintain fully operational during the construction period. The paper deals with the main geotechnical features of the project and in particular with the diaphragm wall and bored pile construction at the Voor-plein and the De Ruijterkade sections of the Central Station.

Jan 1, 2006

By S. S. Gajin

The paper deals with parametric vibrations of an axially loaded pile. The dynamic model is derived by means of Hamilton's principle and reduced to a partial differen­tial equation with variable coefficients and corresponding initial boundary conditions, taking into account the influence of the axial force. By means of Galerkin's method, the partial equation is further reduced to a Matheu-Hill's matrix partial differential equation of the second order. Since the problem of the dynamic stabili­ty has been expressed only for standing piles, the paper analyses in detail two stan­ding piles, one which is restreined, whereas the other is hinged at the toe. In both cases it is assumed that head horisontal displacement is prevented. Using Ruunge-Kutt's method, a computer analysis in the time domain is given for the characteristic parameters and possible boundary conditions. The paper analyses the stationariness of the process, as well as the dependance of the critical excitation frequency upon the pile parameters. The results have been illustrated by respective diagrams.

Jan 1, 1989

By David Pierce

The Port of Seattle, one of the largest on the west coast of North America, made a strong statement regarding their support for reusing existing structures when a decision was made to rehabilitate Pier 69, on Seattle's downtown waterfront, for their new headquarters. Because of its age and location, the pier provided an unusual challenge to the Port and its consultants. The Port hired Peratrovich, Nottingham, and Drage Inc. to design the seismic strengthening of the pier itself. To remedy the lack of seismic resistance in the 70-year-old pier, PN&D designed a new steel-pipe-pile supported concrete apron next to it. The structure relied on a development by PN&D, the "spin-fin pile", to achieve the tension capacities required of the batter piles. The construction of this apron was completed in October of 1991. Another team of consultants performed the superstructure renovation design, which is now under construction.

Jan 1, 1992

By Brian Wilson, Franz-Werner Gerressen, Johannes Reinisch

Specifications for traditional auger mixing methods have made use of the Blade Rotation Number (BRN) to establish acceptable levels of mixing. Cutter Soil Mixing (CSM) has no such established parameter. Previous research has proposed the adoption of an Energetic Mixing Index for CSM and has attempted to establish a basis for this utilizing results from a limited number of panels. This paper reviews the basis of this previous proposal and assesses the applicability of the proposed index utilizing a review of production data from a number of sites in proximity to Vancouver, British Columbia, Canada. Based on the outcome of the review, the paper proposes adoption of a new index for initial field quality control of CSM operations.

Oct 31, 2023