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By James Su

The Green River Valley in Kent, Washington, is a fast growing area containing retail facilities, warehouse factories and industrial businesses, including the Boeing Space Center. Traffic from Interstate - 5 to the West Valley Highway is highly congested. Accordingly, a new corridor, including a bridge across the Green River, was designed and constructed between 1996 and 1997. This paper presents a case history of the design elements and issues associated with the construction of the pier foundations of the bridge. Subsurface conditions were evaluated using both deep test borings and CPT soundings to evaluate the strength and consolidation properties of the supporting soils. Subsurface conditions consisted of alternating layers of loose and medium dense silty sand and sandy silt. Engineering analysis included an assessment of liquefaction as well as pier supporting capacity and associated settlement. The constructed foundations included 6-foot-diameter piers cased to a depth of 120 feet below the ground surface. The pier casings were driven to the design tip elevation and the soil inside the casing was removed by drilling. Despite performing borings and CPT soundings at specific pier locations, occasional trees, buried thousands of years ago through geologic processes, were surprisingly encountered during pier construction. This presented unique and difficult driving and drilling conditions. During drilling, the water level inside the piers was maintained near the ground surface to create a balance of hydrostatic pressure and prevent boiling of soils the bottom of the casing. After the casings were installed, the soil inside the casing was excavated, the rebar cage was installed and the pier was filled with concrete using treme techniques. Construction of the piers is complete and the completed piers have experienced negligible settlement. Owner: City of Kent Engineering Department Timothy La Porte, Project Manager Kent, Washington General Contractor: Mowat Construction Company, Kirkland, Washington Foundation Contractor: Condon - Johnson & Associates, Inc., Tukwila, Washington

Jan 1, 1998

By Ahmad F. Souri, Murad Abu-Farsakh

"In this study, the static lateral resistance of vertical and battered pile groups was analyzed using 3D finite element analysis. The battered pile group finite element model was verified using the results from a case study performed on the M19 pier foundation of the I-10 twin span bridge in Louisiana. The vertical pile group model was created by adjusting pile inclinations of the verified battered pile group model. The finite element models utilized nonlinear constitutive models for materials behavior and a soil-pile interface model. The results showed that the battered pile group had greater lateral resistance than the vertical pile group with 60-70% lower pile cap displacement. The largest lateral load share was found in the middle rows in the battered pile group, while it was in the leading row for the vertical. The soil resistance profiles showed that the vertical pile group mobilized greater soil resistance compared to the battered pile group.INTRODUCTIONThe lateral resistance of a pile-soil system depends on both pile stiffness and soil reaction. The soil reaction is a nonlinear function of deflection, depth, pile stiffness, and soil stiffness and strength. The lateral capacity of single piles is evaluated at the maximum deflection limit, and can be predicted using established methods such as the p-y curve method (e.g., Matlock 1970, Reese et al. 1974), elastic solution by Poulos and Davis (1980), the strain wedge model (Ashour et al. 2004), and the finite element method (e.g., Yang and Jeremic 2002, Comodromos and Pitilakis 2005, Isenhower et al. 2014). For pile groups, the lateral capacity of a pile-in-group is less than the isolated single pile case because the soil in front of the pile-in-group is weakened by the overlap of stress zones from surrounding piles. The latter is referred to as the shadowing or group effect (Fig. 1). Prediction of the lateral capacity for pile groups is based on the p-y curve method for single piles with the use of empirical factors called “p-multipliers”. The p-multipliers accounts for the shadowing effect, and are a function of pile-pile spacing and soil type (e.g., Brown et al. 1987, 1988, McVay et al. 1995). Moreover, the lateral capacity of pile groups is also influenced by vertical load, piles arrangement, and slenderness ratio (e.g., Rao et al. 1998, Patra and Pise 2001, Ilyas et al. 2004, Hussien et al. 2012).Battered piles refer to piles installed at an angle with respect to the vertical to increase their lateral capacity. The greater lateral resistance is achieved by the additional axial reaction in the pile. Battered piles are called “negative battered” when inclined in the load direction, and “positive battered” when inclined opposite to the load direction (Fig. 1). Previous studies concluded that the lateral resistance is highest in positive battered piles followed by negative battered and vertical piles, respectively (Murthy 1964, Meyerhof and Yalcin 1993, Zhang et al. 1999)."

Jan 1, 2017

By Eric Lindquist, John Compagnone, Gabriel Carvajal

"Condon-Johnson & Associates, Inc. (CJA) with the assistance of design consultant, Brierley Associates, designed and installed a water tight shoring system utilizing several ground improvement techniques jointly. Prior to the installation of the shoring system, a test program consisting of the installation and testing of 7 jet grout columns; 1 soil mix panel; 7 soil anchors and 3 tie downs was performed to verify design assumptions. State-of-the-art quality control measures were employed throughout the project.The shoring system consisted of:•,Deep Soil Mixing (DSM) wall utilizing triple axis tooling to install overlapping columns along the perimeter of the proposed excavation to a treatment depth of 54 feet.•,Installation of steel piles in DSM to provide rigidity to the wall.•,Installation of a jet grout bottom seal, installed from surface to a depth of 58 feet below existing grade.•,Installation of 153 soil anchors, 1-1/4” diameter and 47’-6” length, to tie the jet grout bottom seal to the native soil below to resist hydrostatic uplift, installed from existing grade to a depth of 91 feet.•,Installation of walers and pipe struts for internal bracing•,Installation and stressing of 117 tie downs, 1” diameter and 16 ft length, to tie the pump station mat slab to the jet grout bottom seal, installed from inside the excavated pit.Subsurface conditions at the site consist of uncontrolled fill materials to a depth of 20 feet comprised of sandy silt and clayey sand. The native soils underlying the fill generally consist of soft and compressible lean clay and silt with varying amounts of sands to a depth ranging from approximately 44 to 54 feet below ground surface, which in turn are underlain by dense to very dense silty sand. The groundwater elevation at the site is approximately 8 feet below ground surface.This paper covers the design aspects, construction, and quality control measures undertaken by the geotechnical contractor, with supporting figures.INTRODUCTIONThe owner, County Sanitation District No. 2 of Los Angeles County, designed upgrades to their existing Long Beach Main Pumping Plant Facility. The upgrades consist of a new pump station that includes a reinforced concrete below-grade wet well and dry well, a two-story operations building, two 78-inch diameter pipe inlets, two 42-inch diameter discharge pipelines connecting the existing manifold, two pipe junction structures, two insert-type junction structures, and electrical transformers. This paper focuses on the excavation shoring for the new pump station. The original shoring design concept for the pump station excavation illustrated on the contract plans consisted of pressed in sheet piles, a jet grouted bottom seal with soil anchors, 2 levels of internal bracing, and tie-down anchors to resist hydraulic uplift forces on the buried pump station."

Jan 1, 2017

By Maurizio Siepi, Fabio Santillan, Lyndon Bedford, Carlo Crippa

"Abstract: Wolf Creek dam, on the Cumberland River in Kentucky, US, operated and maintained by the Nashville District of the USACE, is the Corps' largest reservoir east of the Mississippi river. The 1748 m (5,736 ft) long Wolf Creek dam combines earthfill and concrete gravity sections. Construction began in 1941 and was completed in 1950. The dam showed signs of instability in the 1960’s, and in the late 70’s an in-depth project of rehabilitation was undertaken, using both grouting and secant piles. The works saved the dam, but in the late 90’s further signs of distress worried the Nashville district of USACE which, after a study conducted on the water seepage, concluded that construction of a new concrete barrier cut-off wall was needed. In 2009, the $341.4 USD million contract was awarded to TREVIICOS-SOLETANCHE JV.The new wall, located upstream of the concrete monoliths, has a minimum thickness of 60 cm (24 in.), and runs the length of the embankment, into the right abutment, for about 4,200 feet. The founding depth reaches 84 m (275 feet), well below the zone of solutioning. With a total surface approaching 92,903 sq.m (1,000,000 sq.ft), the Wolf Creek barrier wall is unlike any other project in the world.The construction of the cut-off wall followed a complicated but logical sequence of several operations, involving a variety of technologies: grouting, hydromill, directional drilling, and secant piles with reverse circulation. The intensive rock grouting program was aimed to minimize the risk of slurry loss and extend the positive cut-off further deep. Subsequently, an Encasement Concrete wall was installed with hydromill, toeing into the rock, to protect the embankment during the following phases. Smart holes were then drilled into the Encasement wall down to the final depth. Eventually, the holes were used to install the secant piles by employing the reverse circulation piling method.An extensive verification campaign has confirmed the superior quality of the cutoff wall consisting of 1200 secant piles, exceeding by far USACE’s requirements. The main project was substantially completed in early 2013. A small portion of secant piles wall will be installed downstream of the dam, to close the switchyard, finishing the project in the early months of 2014.IntroductionWolf Creek Dam is located on the Cumberland River in south-central Kentucky. The Nashville District of USACE operates this multipurpose dam to provide hydropower, flood control, water supply, and water quality benefits for the Cumberland River system and surrounding region. Lake Cumberland, created by the dam, impounds 7,400 million cu.m (6 million acre foot) at its maximum pool elevation of 232 m (760 ft) above sea level. This lake is the largest reservoir east of the Mississippi and the ninth largest in the United States, and attracts 4.89 million visitors, more than Yellowstone National Park (2.87 million).This paper describes the recently completed works for the rehabilitation of the dam, accomplished by TreviICOS-Soletanche JV with the construction of a new Barrier Wall."

Jan 1, 2014

By Thomas C. Anderson

Tiedback walls are now recognized and accepted as a good solution for a variety of structural problems: ? Retaining Walls and Bridge Abutments in cut situations ? Landslide stabilization ? Repair/support of existing walls Acceptable techniques have been developed for anchoring in cohesive and granular soils and in any kind of rock. Methods have been developed for adequately protecting tieback tendons against corrosion and for testing every tieback to verify its long-term load-carrying capacity. However, the major problem that the industry faces today is how do we get constructable and economical tiedback walls contracted for and built with minimal claims. This paper will explore the issue of "constructability" through a look at specific problems from actual projects. From a research report from the Construction Industry Institute, Austin, Texas (1986), constructability is defined "as the optimum use of construction knowledge and experience in planning, design, procurement and field/operations to achieve overall project objectives." Maximum benefits occur when people with construction knowledge and experience become involved at the very beginning of the project." The design and installation of tiebacks has been developed primarily by specialty contractors; each contractor has evolved its own methods of performing the work, and consequently, many of the techniques are patented and proprietary. The real question is, how do we make effective use of this knowledge and experience during the design phase of the project?

Jan 1, 1991

By Adnan A. Malik, Tadashi Maejima, Jiro Kuwano, Shinya Tachibana

"The helical piling system provides solution to many geotechnical related problems due to its quick installation, higher compressive and pullout resistance, no wastage of material, workable in limited areas and reusability. However, its use as a foundation for bridges and high-rise buildings is still limited as compared to other piling methods. In the present study, the performance and load settlement behavior of screw and straight pile is investigated under cyclic compressive load in dense ground conditions. To achieve the set objectives, pile load tests were conducted in a cylindrical steel container. The model ground was compacted with dry sand at relative density of 80%. It is observed from the test results that screw and straight pile resistance reduced when the cyclic load is applied at allowable pile resistance state. The reduction in the ultimate pile capacity is more in straight pile than in screw pile. However, straight pile showed higher ultimate pile capacity than screw pile under similar pile tip diameter. The effect of helix bending deflection on load settlement behavior and ultimate pile capacity increases under cyclic loading.INTRODUCTIONScrew pile is one of the new developments in deep foundation, which is growing tremendously fast because of its quick installation technique, less noisy operation, no wastage of material and involvement of minimum manpower. Screw piles have an edge on straight pipe piles due to its high bearing capacity and uplift resistance. The installation mechanism of screw pile is different from straight pile. Torque and pressure is required to install the screw pile whereas hammering, pressure and vibration is required to install straight pile. As the installation mechanism is different between screw and straight pile, therefore, the ground disturbance that is produced during their installation is also different. The ground disturbance produced during the installation also depends upon the pile tip condition i.e. open or closed ended. Sakr, (2009) stated that the compressive capacity of screw pile in 3 to 5 times higher than driven piles having the same shaft diameter and length. The reason for this increase in pile capacity is due to helix, which is generally 2 to 2.5 times the pile shaft diameter. Larger helices can give higher end bearing capacity but it requires very powerful machinery to install in dense grounds. For instance, if large helix screw pile is installed in a dense ground then helix-bending deflection will start affecting the end bearing capacity (Yttrup and Abramsson, 2003; Malik et al. 2013 and 2015). According to Malik (2015), the equations of thin plate (Young and Budynas, 2002) with uniformly distributed load on the plate can give reasonable estimation of helix deflection due to dense ground conditions."

Jan 1, 2016

By Charles M. Wilk, Lori Tiefenthaler

"Information presented in this paper can be used to support deep soil mixing, subsurface grouting and slurry wall technology as sustainable construction technologies. Ordinary Portland Cement (OPC) is the default cementitious material used by Deep Foundation Institute (DFI) Members for geotechnical work. Owners, engineers and contractors can contribute to the sustainability of a geotechnical project by increasing the use blended hydraulic cements and industrial byproducts to replace some of the OPC in mix designs. Sustainability is defined as the quality of not being harmful to the environment or depleting natural resources. Production of cementitious materials consumes natural raw materials and energy while also generating air emissions and waste. Life Cycle Assessments can be used to compare the relative environmental impacts of one cementitious material to another. Blended hydraulic cements (BHCs) are interground (or blended) mixtures of Supplementary Cementitious Materials (SCMs) with OPC. Commonly used SCMs include fly ash, ground granulated blast furnace slag (GGBFS) and limestone. Examples of industrial byproducts commonly used in geotechnical work include coal combustion residuals (CCR) (aka fly ash), and ground granulated blast furnace slag (GGBFS). Much of life cycle impact of these SCMs and industrial byproducts have already been borne by the industries that generated them. There is increasing awareness to LCA and sustainability of different materials used on projects. This is evident in the application of the Leadership in Energy and Environmental Design (LEED) program. The savings in environmental impact with the use of SCMs and industrial byproducts can make proposed use of these materials in a geotechnical project more attractive in terms of sustainability. This paper presents (a) information that compares published life cycle assessment data of OPC, BHCs, and slag cement (SC) to illustrate the potential benefits to sustainability and (b) general strategies for positioning a geotechnical application, use, project design or cementitious material mix as a more sustainable alternative"

Jan 1, 2017

By Joseph A. Sopko

There has been a trend in recent years in performing the initial formation freezing using liquid nitrogen (LIN) and then converting the system to circulating refrigerated brine. While proponents of this method state it decreases freezing time, it can also be considered an alternative to inadequate refrigeration capacity. This method was used on several small projects in the 1980s. Problems such as broken pipes, frozen brine, and unsafe work conditions caused contractors to re-think the method. This paper discusses these problems and also presents work schedules showing no schedule reduction. In fact, this method can lead to longer time as well as significantly higher costs. BACKGROUND Ground freezing as a method to provide groundwater control and temporary earth support for excavations is completed using a relatively simple process: drilling and installing refrigeration pipes around the perimeter of the excavation and introducing a coolant into these pipes. The coolant extracts heat from the ground, converting the pore water to ice and forming a strong, impermeable material. A typical ground freezing system is illustrated in Fig. 1. SYSTEMS There are two basic types of coolant systems: circulating and direct expansion. The circulating coolant system is made of two separate, closed systems. The medium circulating is the secondary coolant. It is cooled at a central refrigeration plant, circulated through the pipes, and warms as it extracts heat from the ground. It then circulates back to the plant where it is cooled. This coolant is chilled in a heat exchanger by the primary refrigeration system where a compressor system is charged with a refrigeration gas. The heat is ultimately extracted from the ground and expelled into the atmosphere by an evaporative condenser. Secondary coolants are usually a brine or glycol chemical while the primary refrigeration gas is anhydrous ammonia or another commercially available gas.

Jan 1, 2019

By M. Zanotto

[ ] A period of heavy rains caused the river Adda to flood parts of the Valtellina, one of the Alpine valleys of Northern Italy. The exceptionally high waters put under considerable strain the whole system of embankments and levees controlling the river and protecting the adjacent towns and lands. In some places the water breached and washed away the embankments, submerging large tracts of cultivated land, buildings, roads and railway tracks. The town of Talamona, in the lower Valtellina, was hit particularly hard: in its proximity the river overrun and then washed away 300 m (1,000 ft) of embankment (see vicinity map, fig. 2), depositing large amounts of riverbed debris onto over 400 hectares (1,000 acres) of fertile land.

Jan 1, 1992

By Yvone Franco Crosato

The dense population of Hong Kong requires the construction of tall buildings in reclaimed areas or perched on the slopes of the many hills. The large loads to be supported are carried by deep foundations. Many of those are bored piles, to rock, of diameters up to the 3.0 m. of today.

Jan 1, 2000

By Hidekatsu Takeuchi, Masaru Sakakibara, Shigeo Tanabe, Kenji Harada, Akihiko Suzuki, Shoji Morihana

"Deep mixing (DM) method, one of the most commonly used solidification methods, is based on the principle of solidifying soft ground. It can be classified into two categories such as Cement Deep Mixing (CDM) method and Dry Jet Mixing (DJM) method which apply hardening agent in slurry condition and in powdery condition respectively. In recent years, DM methods have undergone changes that have evolved them from the traditional method to meet the needs of the diversifying market. Among them, the Contrivance-Innovation Clay Mixing Consolidation (CI-CMC) method is a DM method which mixes a cement-type hardening agent in slurry condition mechanically with soils in situ and incorporates the innovative technique, “atomized ejection” that has been developed to allow faster installation of larger diameter columns without sacrificing quality compared with conventional methods. At this technique, the atomized hardening agent is discharged together with compressed air through a device incorporated into the mixing blade. It also has advantages of performing the works with low-displacement of the surrounding soils in consideration of environmental friendliness and with higher penetration capability against hard ground.This paper presents the technological outline of the above-mentioned CI-CMC method, focusing on the atomized-ejection technique, followed by some construction examples, applied to the self-earth-retaining wall, to the hard ground and the area adjacent to the existing structures.INTRODUCTIONAccording to the accumulation of its case histories, Deep Mixing method has been receiving the demands of its application to more challenging conditions, such as harder ground condition, and requirement of lower displacement of the surrounding ground during its operation. In addition, to match its price against the other cheaper methods and widely receive its benefit of higher quality, the cost reduction of Deep Mixing is also one of the major challenges. For the cost reduction, higher productivity and lower consumption of the material to obtain the equivalent strength and homogeneity with the conventional method are required.The Contrivance-Innovation Clay Mixing Consolidation (CI-CMC) method has been developed to meet these demands. CI-CMC incorporates the mist ejection that has been developed to achieve faster installation of larger diameter columns without sacrificing quality compared with the existing methods. Normally, we obtain cement columns of about 1.0 m in diameter by using Deep Mixing method. To increase the productivity, it is not preferable to drastically increase the penetration and withdrawal speed of the mixing blades because of the hardness of the ground and restriction by minimum number of passage of rotating blades per a certain height of the soil cement. Instead, the expansion of diameter of the columns will simply increase the productivity. The development of the new mist ejection system, as shown in Photo 1, has enabled the diameter of soil cement columns to 2.0 m on single axis while 1.6 m on double axes. Mist ejection means that the hardening agent slurry is sprayed into the ground in mist form together with compressed air thereby achieving homogeneous mixing and reducing the resistance on rotating blades."

Jan 1, 2015

By Javaid M. Alvi

This paper is an attempt to outline the emergence of Augered Cast-ln-Place piles as one of the more economical types of foundation for supporting high-rise buildings and heavily loaded structures recently constructed in the flood plains in and around the Greater Pittsburgh area. To understand the process of selecting foundation types, it is important to understand the general geology of the area and past construction activities that have taken place in the flood plains, especially along the riverbanks, during the last century. The first part of this paper presents a brief description of the general geology of the area; the second part of the paper concentrates on the historical evolution of the use of deep foundations and selected case histories; and the last part presents the results of load tests on large diameter Augered Tremie Concrete (ATC) Piles placed in sandy alluvium which suggests a much larger load-carrying capacity of these piles and also provides an insight into their future application. 2.0 GENERAL GEOLOGY 2.1 Soil Overburden Most of the high rise buildings in the Central Business District as well as along the North Shore and South Side of Pittsburgh are situated in the flood plain at the confluence of the Allegheny River and the Monongahela River where their combined flow forms the Ohio River. The flood plain consists of unconsolidated deposits of Quaternary age that overlie the bedrock of Pennsylvanian age. These deposits are called alluvium or valley fill, and include moderately to poorly sorted clay, silt, sand, gravel and some boulders. Their thickness varies from zero at the edges of the valley to about 80 feet towards the rivers (Figure 1).

Jan 1, 2001

By Frederick C. Rhyner

This paper describes the design and construction of two high-capacity rock anchors to restrain a supplementary backstay for the Bear Mountain Bridge, which is a suspension bridge spanning the Hudson River about 40 miles north of New York City. The supplementary backstay was installed to relieve a portion of the tension in the southern main cable, which had been creeping in recent years. The two new rock anchors were 1,200 kip capacity each, installed at a batter to depths of 59 feet. This paper describes the subsurface investigation, group capacity analysis, installation and load testing. The rock anchors included strain gages connected to the monitoring system for the bridge. The paper describes the long term strain gage data which shows no change in stress distribution in either anchor.

Jan 1, 2010

By D. A. Bruce

The use of small diameter cast-in-place bored piles is becoming increasingly popular in the United States. Such inserts are used as conventional load bearing piles, and are generally referred to as pin piles. The other major application is for the in situ reinforcement of soil slopes or excavations. The paper reviews the applications, construction, design and performance of inserts of each type.

Jan 1, 1989

By Abolfazl Eslami, Masoud Zare, Ali Asadi, Ali Abrang

"Physical small scale models for study of deep foundations can be performed in simple chambers (1g), calibration chambers (CC), and centrifuge apparatus (ng) which involve some limitations and difficulties. In recent years, Frustum confining vessels (FCV) have been developed for physical modeling of deep foundations. This device is frustum of a cone shape that applies a steady pressure on its bottom and creates a linear stress distribution along its vertical central line. A new FCV which has been built in AUT is introduced. This device has a height of 1200 mm, top and bottom diameters of 300 and 1300 mm, respectively. Through the application of bottom pressure up to 300 kPa, the insitu overburden stress conditions equivalent up to 40 m soil deposits consistent to the embedment depth of commonly used piles. Observation indicated that there is approximately a linear trend of stress distribution, and this device can create realistic overburden stress in the desired control volume along the central line. Moreover, a couple of compressive and tensile load tests were performed on steel tubular open end model piles driven in sand with length of 750 mm and different diameters and L/D ratio between 8-15. Comparison of load capacity between tested and full scale piles demonstrate a suitable conformity for similar confinement conditions. Therefore, the FCV can be realized as an appropriate apparatus for investigation of piling geotechnical behavior and examination of construction effects.IntroductionDeep foundations are designed as foundation system for supporting heavy loads, high rise and important structures. Different theoretical, numerical and experimental approaches have been developed to study the geotechnical behavior of deep foundations. Experimental methods are employed to clarify directly pile-soil interaction and because of repeatability, analogy, rapid measurement and cost efficiency, physical modeling can be realized as an intermediate technique compared to element testing and full scale load tests."

Jan 1, 2015

By Darrell L. Beddard

The Loma Prieta earthquake occurred on October 17, 1989 at 5:04 PM, Pacific Daylight Time. It measured 7.1 in magnitude and was felt from Los Angeles north to the Oregon state line and east to western Nevada. The epicenter of the earthquake was located along the San Andreas Fault, in the Southern Santa Cruz Mountains just north of the City of Watsonville, California. It was the largest earthquake to occur in the San Francisco Bay area since the 1906 earthquake. A total of 87 aftershocks of Magnitude 3.0 or larger were recorded within 21 days after the seismic event. As a result of this earthquake thirteen State-owned and five locally-owned bridges were closed to traffic. Three of the most publicized State-owned structures closed to traffic were Struve Slough Bridge, San Francisco-Oakland Bay Bridge and Cypress Street Viaduct. Struve Slough Bridge was twin slab bridges that collapsed and were rebuilt and open to traffic three months after the earthquake. San Francisco-Oakland Bay Bridge experienced collapse of upper and lower spans at Pier 9 and was reopened to traffic one month after the earthquake. The Cypress Street Viaduct experienced collapse of 48 bents that resulted in the upper roadway falling onto the lower roadway.

Jan 1, 1996

By Matt Fenwick, Douglas R. Schwarm

Stringent underwater noise limits at the Fairview Ave. N. bridge replacement on Seattle's Lake Union required an innovative approach to supporting the 470-ft long drill trestle. Screw-in foundations would reliably mitigate noise, but the required 500-kip bearing resistance were an order of magnitude higher than typical helical piles. This paper describes the process of designing, installing, monitoring, and testing 22-inch dia. helical piles 80 feet long with 36- and 42-inch dia. helices. A static load test confirmed that the conventional k-factor design method can be extended to capacities of up to 800 kips. A 375 ft-kip drive mechanism had to be fabricated because no North American equipment could supply the necessary installation torque. Real time installation monitoring and later "re-torque" tests confirm that helical piles gain capacity with time, analogous to driven piles under restrike. Underwater and on-land measurements confirmed very low noise, suggesting the possibility of widespread adoption where similar limits are imposed. Overall, this case history illuminates the need for innovative deep foundation types in response to ever-increasing regulatory constraints.

Sep 8, 2021

By D. Barber, A. D. Miller, P. A. Bray

The project was to develop an area within the existing West County Wastewater Treatment Plant which would enable the construction of a new Raw Wastewater Pump Station (RWPS) with a footprint of approximately 85 feet by 190 feet and a foundation depth of about 82 feet below grade and a new Short- Term Detention Basin (STDB) with a footprint of about 80 feet by 130 feet and a foundation depth that varied from approximately 3 to 24 feet below grade.. The excavation support system had to be designed to withstand both normal and the 100-year flood elevations. A Reinforced Soil-Cement Wall (RSW)was chosen to provide a hydraulic barrier which consisted of a single row of soil-cement elements installed along the perimeter of the area to be excavated. Steel wide flange beams were installed on 4 foot centers to support construction loads and be resistant to the lateral forces of the soil and hydrostatic pressures. The RSW was installed to a maximum depth of 104.5ft using a triple-auger drill rig with mixing paddles with a 2ft key into weathered shale providing a cutoff wall consisting of 53,150 square foot of treated soil. The project was to provide the initial design of the excavation support for the pumping station excavation support system and groundwater cutoff. There was 534 linear foot of soil-cement-bentonite wall installed and 106 - 80 foot long W21 x 121 wide flange beams installed on four foot centers into the alignment of the wall. Each element was drilled down into the weathered shale to obtain groundwater cutoff. Derek R. Guthrie Water Quality Treatment Center Pumping Package is the site for a new pumping station that will service Louisville, Kentucky residents. After unplanned long term exposure into the winter, the effects of freeze thaw cycles were evident.

Jan 1, 2017

By Filippo Maria Leoni, Alessandro Bertero, Gianluca Pianezze

"As part of the Southeast Louisiana (SELA) drainage program, designed by the U.S. Army Corps of Engineers (USACE) to reduce flood damages in the City of New Orleans and surrounding parishes through the construction of new pumping stations and better drainage canals, the SELA-22 project entailed the installation of a concrete covered canal along Jefferson Ave. and Prytania Street, in a highly urbanized portion of Uptown New Orleans, LA. The scope of the required soil improvement was to replace the soil between two parallel lines of sheet piles with a soil-cement mass to eliminate underseepage and provide structural support for the concrete culvert. The USACE selected the jet grouting (Jet Grout) technology for the construction of the bottom plug. The bottom plug is between 18 and 21.5 ft thick with a maximum depth of approximately 40 ft, for a total length of approximately one mile. The treated soil comprised soft clays and silts with occasional presence of sands. Project specifications required 100% area coverage, a 28-days unconfined compressive strength of 100 psi and hydraulic conductivity of 1x10-6 cm/s, to be verified by testing specimens from cored samples. The specialty geotechnical contractor proposed to accomplish the task utilizing their proprietary and innovative elliptical bi-fluid Jet Grout technology, and elected to perform a pre-construction bench scale laboratory mixing program to determine the most suitable grout mix features (i.e. binder type and proportions, binder content, etc.) to be applied in the subsequent field test and production stages. This paper will summarize and compare the results obtained from the different pre-construction and construction stages; interpretations of the data will be provided, along with general considerations regarding the effectiveness and significance of bench scale testing for jet grouting applications.INTRODUCTIONIn general, the effectiveness of the construction parameters in any ground improvement work depends largely on the physical and mechanical properties of the soil to be treated. Therefore, well designed laboratory and field test programs, aimed to disclose the interaction between the site-specific soils and the mixing parameters, are essential to achieve the desired end product."

Jan 1, 2016

By Alexander J. Verstraeten

Work started on the building of the Amsterdam Concert Hall in 1880 by driving over 2000 wooden piles of 13 m on which foundation-beams out of wood and brickwork were made. During construction the design was changed. This was due to the latest German developments, requiring double walls instead of single, so that the space in between could be used for ventilation and heating. Therefore the pile load, originally designed at approximately 100 kN, increased even to 170 kN for some piles, causing settlements and unacceptable cracks in the brickwork. Settlements of up to 18 cm were measured. In 1985/1986 around 400 vibration-free Tubex-displacement-piles were installed under the Concert Hall, with a shaft of 0355 mm, a pile shoe of 0560 mm and a pile length of approximately 18 m. After these Tubex piles had been installed they took over the complete weight of the whole building, thus eliminating further settlements and damage. 95% of all the construction activities took place while the concerts went on. The chosen solution also made it possible to create a new basement under the Concert Hall as an extension for dressing-rooms etc.

Jan 1, 1987