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By Ray Zelinski

Caltrans sponsored a research project in 1992 which incorporated proprietary and generic pile types. The piles were subjected to axial tensile/compressive loads in deep, soft soils. Descriptions of various pile types and systems, scenarios leading to the proposal to test the systems, and load test results were/will be provided by other presenters at this seminar. Therefore, this paper will focus on the issues surrounding use of test results and proprietary pile systems on Caltrans construction projects. The primary issues facing Caltrans during implementation are as follows: 1) producing pile cap designs for a range of pile types and loads; 2) providing construction specifications which allow fair competition among the system vendors, yet assure design and ultimate capacities; 3) Develop quality control standards for pile system materials and installation techniques which guarantee pile durability for static and dynamic loads; and 4) assure that foundations have adequate lateral capacity.

Jan 1, 1993

By Harald P. Ludwig, Matthew J. Niermann

The support of excavation (SOE) for the Capitol Crossing project in Washington, DC consisted of a combination of soldier piles, lagging, tiebacks, braces, underpinning, single auger soil mixed (SASM) walls, micropiles, and a tiedback slurry wall. Over 130,000 square feet of SOE was installed with more than 1,300 tiebacks providing lateral support for excavation depths of up to 72 feet. Several structures including the Holy Rosary Church, the Bell Tower, the Casa Italiana, and a modern office building were supported by a combination of conventional hand dug underpinning pits, bracket piles, and stiff SASM walls. This paper will focus on the design and performance of the SOE adjacent to the Holy Rosary Church and the Bell Tower. Deflection-based design was used to estimate the movements of and limit damage to these structures. An extensive monitoring program was used to provide real time movement data. The results of

By Sebastian Fischer, Rolf Katzenbach, Steffen Leppla

"The risk management in the case of liquefaction is one of the most serious and also difficult issues in geotechnical engineering because failure caused by liquefaction is always a sudden failure without ahead indication. For that reason ground improvement technologies for the prevention of liquefaction are necessary. The paper explains the responsible and effective risk management. Methods for the risk management and stabilizing the soil sustainably are described in detail.1. INTRODUCTIONDue to population growing more and more settlement area is needed, which is often including improper regions (e.g. mountain and coast regions) with raised risk of various kinds of disasters. But also in densely populated areas the risk of disasters like landslides can occur. One reason for the raising of risk in densely populated regions can be the opencast mining for raw material production. An essential element of the opencast mining is the loose deposition of the removed overburden, the so-called “overburden dump”. When an opencast mining is running out of the raw material, an opencast hollow remains in landscape. The slope areas of these hollows mostly consist of loose bedded material of the overburden dump. Due to the end of groundwater conservation these loose bedded slope areas are flooded. In consequence the slopes are in extreme danger of becoming liquefied. The result of a liquefaction in these slopes will unavoidably be a slope slide. Such a slope slide can extend up to several hundred meters into the landscape and can move several million cubic meters of material. An upsetting example for such a landslide is the slope failure in the German city of Nachterstedt on July, 18th 2009, which made necessitate remedial measures and also prevention works for the further utilisation of the region. The phenomena of liquefaction is not limited of slopes in series of opencast mining. Especially in regions with a highly appearance of earthquakes the phenomena of liquefaction is well known.2. RISK MANAGEMENTAn essential part for the stability assessment of slope systems is the investigation of sensitivity against liquefaction. In the case of given sensitivity against liquefaction there is no calculation method according to soil mechanics to determine the factor of safety against slope failure. Just for the case that sensitivity against liquefaction is not met, a comparison of the load (effect) E and the resistance R which is the traditional verification of stability against slope failure, can be calculated (Figure 1)."

Jan 1, 2015

By Scott M. Mackiewicz

This project includes replacement of the historic vertical-lift span Meridian Bridge (U.S. Highway 81 over the Missouri River) that connects Yankton, South Dakota with rural Cedar County, Nebraska. The new 76-foot wide, 1,590-foot long steel plate girder structure required the use of drilled shaft foundations that extended into the underlying Carlile Shale formation. Designers indicated that an individual drilled shaft capacity of about 2,000 kips will be needed at each of the river piers, and based on the subsurface information, 8 to 10-foot diameter drilled shafts extending to about 115-foot would be required for support of the bridge structure. An Osterberg Load Test was performed on one test shaft to determine the ultimate skin friction and end bearing of the Carlile Shale. This paper describes the design and installation of the load test drilled shaft as well as presents the load test results as compared with predicted design values determined using FHWA methods.

Jan 1, 2008

By Justin Phillips

The redevelopment of Bow Bells House in London has thrown up a number of challenges that will increasingly be faced by developers of congested sites. In the context of pile reuse this paper examines four key issues: 1. The Developer?s perspective on sustainability, cost, programme and risk management. 2. The nature of pile testing including timing, the balance of extent of intrusive works whilst retaining the existing piles and identifying representative levels of testing. Four key elements of investigation; geometry, integrity, durability and capacity are evaluated. 3. In terms of design this paper supports the adoption of alternative probabilistic methods aligned with communicating to Clients in terms of acceptable ?probability/risk of failure? in place of a factor of safety approach. 4. The project also highlights a number of issues that will require greater attention to maximise the future reuse potential such as foundation load transfer platforms and promoting developments based on early collaborative framework design and contracting across the supply chain.

Jan 1, 2008

By Michael D. Justason

This paper describes the technology behind the development of an automated energy control system for a diesel pile hammer. Some background is given on experience using an energy monitoring system on the Route 1/I-95 interchange in Alexandria, Virginia. An adjustable hammer throttle and feedback from an energy monitoring system was then used to create a fully automated hammer energy control system. The performance of this system is described in reference to a piling project in Canada where the automated energy control system was used to obtain an unprecedented level of quality control and assurance ? data and graphs from the project are presented. The hammer energy control system (ECS) was used to successfully control and maintain a prescribed impact energy for the diesel hammer. This paper presents the first ever results from a truly automated diesel pile hammer and points to a new direction in quality control and assurance in pile driving.

Jan 1, 2006

By Mehih Demirkan, Kevin Tehansky

Located about an hour drive south from Washington, D.C., the Maryland Transportation Authority (MDTA) contracted with Skanska-Corman-McLean (SCM) to deliver a new Governor Harry W. Nice Memorial/Senator Thomas "Mac" Middleton Bridge, which takes U.S. 301 over the Potomac River, spanning 1.9 mi (3 km) from Maryland to Virginia. The new bridge aimed to improve capacity, safety and access of the roadway and was planned as a four-lane span with deep foundations that would be constructed fewer than 150 ft (45 m) north of the existing alignment of the more than 80-year-old bridge. The new Harry Nice Bridge opened in the fall of 2022 with a design life of more than 100 years, servicing 12 ft (4 m) wide lanes with 2 ft (0.6m) shoulders, doubling capacity, enhancing emergency response, upgrading maintenance and inspection activity access, and featuring lane sharing for cyclists.

Apr 1, 2023

By Nathan Iverson, Allie Brady

Located on rolling bluffs on the Zumbro River's south fork in Southeast Minnesota, Rochester is the state's third largest city and is the home and birthplace of the renowned Mayo Clinic, a nonprofit academic medical center focused on integrated health care, education and research. Mayo Clinic employs more than 4,500 physicians and scientists with another 58,000 administrative and allied health staff across three major campuses: Rochester, Minnesota; Jacksonville, Florida; and Phoenix/Scottsdale, Arizona. Originally developed as a stagecoach stop, Rochester has become a national destination for medical care, drawing more than two million visitors annually to Mayo's Minnesota location. Since January 2022, Veit & Company has been working on the construction of the Mayo 1st Ave Tunnel, which comprises three tunnels (pedestrian, utility and services), and the RMC Loading Dock projects in Rochester. These adjacent projects are on the Mayo Clinic's ever-expanding campus and represent its continued dedication to improvement and advancement as a leading medical service provider in the industry.

Jan 1, 2023

By Dawn Shuttle

In trying to find a grout, or some kind of stabilizer that would work in this application, we established some performance criteria. Of those, what I controlled the most was viscosity, then I had a whole list of other criteria. I needed a long, controllable gel time, durability and the ability to set and stabilize the soil. So I looked through a lot of different stabilizers, some really crazy ones and also the typical chemical grouts that are used. The typical chemical grouts were eliminated because of long-term durability concerns, the need for having extended gel times, and several other concerns. I would be happy to discuss that with you further after the talk if you're interested. But, generally it was based on viscosity, gel time, and the need for extended gel time. In terms of the relative density of the sand many other grouts could have been used. But the main issue was trying to develop this way to do low pressure grouting that would not cause invasive disruption of the site. We couldn't go in and grout it, put centers, so most of the other grouts wouldn't work for various reasons. The forty percent relative density samples were prepared by plubiation. That was both during the cyclic testing stage of the research, which happened a few years back, and also during the box model and the laminar box models at RPI. In terms of what criteria were used to determine the success of the grouting, when I initially started this work what I did was take the grouted samples and I subjected them to cyclic triaxial testing. What I did was take a look at the cyclic deformation resistance of different concentrations of grouted colloidal silica treated sand. I looked first at 20% concentration because I wanted something that I knew worked and then I gradually decreased to 15%, 10%, and 5%. What I was most concerned with was that it did not liquefy and that it was able to hold together it and experience some deformation. But most importantly it needed to not liquefy. So, that was the biggest issue in determining the success of the grouting. In terms of the centrifuge modeling it was done by looking at several components: from looking at the pictures of the bending moments, looking at the acceleration records and how the acceleration records were transferred through the soil, looking at the reduction in the lateral displacement and those kinds of issues. So let me show you the difference.

Feb 10, 2003

By James P. Hambleton, Anastasia Nally

This work focuses on the numerical simulation of multi-plate anchor systems (e.g., helical anchors) in sand subjected to vertical loading. In assessing the stiffness and capacity of these multi-plate anchor systems, full awareness of the abilities and limitations of the various analysis methods must be understood. This work first summarizes studies completed by others and then goes on to assess the failure mechanisms of multi-plate anchors in sand and the influence of (1) plate width-to-depth ratio, (2) number of plates, and (3) relative positioning of plates. The analysis makes use of (1) conventional limit analysis, (2) so-called modified limit analysis that employs reduced strength parameters to account for the influence of soil dilatancy, and (3) the displacement-based finite element method, which considers elastic as well as plastic deformation leading to failure. The work critically reflects on limitations in the current analysis methods for helical ground anchors. INTRODUCTION Helical anchors are a relatively low cost foundation type, typically consisting of a steel rod and single or multiple plate attachments. In recent decades, they have seen rapid growth, and as outlined by Merifield and Sloan (2006) and Hambleton et al. (2014). Design techniques for helical anchors have previously been predominately empirical, as much of the past research in this field is experimentally based. It is common practice for helical anchors to be modeled as horizontally oriented plate anchors in both numerical and experimental analysis. This work focuses on analysis based on the finite element method, including so-called finite element limit analysis and the conventional displacement-based finite element method, with some comparisons made to experimental studies. Numerical simulation of anchor pull-out capacity in cohesionless soils is stunted by the many difficulties faced when using numerical analysis with cohesionless soils. Additional variations can be seen when comparing the serviceability based load capacities to the ultimate load. In this work, both the force-displacement response (stiffness) and the ultimate anchor capacity are assessed, with more focus on the latter. This work focuses only on analysis techniques for multi-plate anchors with vertical loading in cohesionless soils. Many studies have been completed in this area, some of which assume a rectangular plate in a plain strain model (Rowe & Davis, 1982; Merifield & Sloan, 2006; Cerfontaine et al., 2019). Whereas others use axisymmetric conditions (Baker and Kondner, 1966; Saeedy, 1987; Murray & Geddes, 1987; Ghaly & Hanna, 1994; Sakai & Tanaka, 1998; Merifield et al., 2006;) and minimal studies considered both axisymmetric and plane strain in the one study (Vesic, 1971; Tagaya et al., 1988; Murray & Geddes, 1987; Sarac, 1989).

Jan 1, 2019

By N. V. Nayak

Konkan Railway Project is one of the most ambitious railway construction projects in India, involving construction of a 760.km long, Broad Gauge (1676 mm), single track railway line, connecting Roha in Maharashtra State with Mangalore in Kamataka State. The railway line travels along the Western Coast of Indian subcontinent, through states of Maharashtra (382 km), Goa (105 km) and Karnataka (273 km) (Fig.1). The project alignment traverses through one of the most formidable terrains ever encountered, in the history of railway construction in India. In the State of Goa only, railway alignment is crossing 6 major rivers Terekhol, Chapora, Mandovi, Zuari, Sal and Talpona. Zuari Railway Bridge (1305.6 m), Mandovi Railway Bridges (I and II) (1182.7 m) rank as 2nd and 3rd long bridges, (first longest bridge being Sharavati Bridge (2.2 km} at Honavar) which have been constructed on Konkan Railway. All these three bridges have been constructed by M/s.Asia Foundations and Constructions Ltd. (AFCONS). This paper presents, case history of construction of pile/caisson foundations for Zuari and Mandovi Bridges.

Jan 1, 1996

By Bengt H. Fellenius

An upgrading and straightening of a highway included building a bridge across a small river. A routine site investigation was initiated to determine the conditions for designing the foundation of the bridge. The proposed bridge was a two-lane highway bridge in one span with a total length of 30 m (100 ft), as indicated in Fig. 1. It was to be placed about 20 m (66 ft) upstreams of the bridge for the existing highway. The site investigation included one boring at each abutment with soil sampling and in-situ vane testing and placed about halfway up the slope from the small river at ground surface elevation + 54 m. Within the investigated maximum depth of 40 m (130 ft), the soils at both borehole locations consisted of a thin clay crust over a thick deposit of soft sensitive clay with a natural water content of about 70 % and a liquid limit of about 60. The undrained shear strength below the crust was about 20 KPa (400 psf) and increased slightly with depth. The sensitivity was high, about 40.

Jan 1, 1987

By Michal Topolnicki

Deep Mixing Series: This article is the second keynote highlighted from DFI's virtual Deep Mixing Conference in 2021, for which Topolnicki served as a committeee co-chair Polish applications of deep soil mixing (DSM) technology occupy a leading position in Europe. That includes use for road and railway embankments, bridges, residential and industrial build- ings, silos, commercial centers, slabs, car parks and storage yards, excavation supports and cut-off walls. In fact, more than 350 road and railway viaducts and 200 wind turbines have been founded nationally on DSM columns, which are firsts on an international scale. This represents more than 1,200 imple- mentations by the Polish geotechnical industry. Considering the need to update DSM design recommendations, this article will attempt to summarize the best practices of wet DSM design and implementation, in particular. It draws on 20 years of experience and will high- light the properties and principles of the design of stabilized soil and lessons learned. Case studies are included to fur- ther understanding of the careful con- siderations needed with this technology.

Apr 1, 2022

By Ping Yang, Tian-bin Li, Min-hui Wu

"The process of filtrate loss of low solid-phase drilling fluid at different content of polyanionic cellulose is investigated by the standard filtration test. The test results showed that when time of filtration is same, the filtrate volume decreases linearly with the increase of content of polyanionic cellulose. When content of polyanionic cellulose is same, the velocity of filter loss decreases nonlinearly with the increase of time and the velocity of filter loss will reach a stable value. The filtrate volume in 7 to 8 minutes can reach half of the total filtrate volume. At the same time, the velocity of filter loss of drilling fluid decreases nonlinearly with the increase of viscosity. When apparent viscosity is between 3.5~4.15 mPa.s, decrease speed of velocity of filter loss is quick. The results are helpful for characteristics evaluation of filtrate loss of drilling fluid and control of filtrate loss.IntroductionDuring the process of drilling, water of drilling fluid can leakage into stratum, the water can result in instability and collapse of borehole wall. At the same time, the original ratio of drilling fluid will change. The density of drilling fluid will increase, the performance of the drilling fluid will change. Controlling amount of filtration is important to drill successfully. The additives of controlling filtrate loss are mainly two types, particle materials and polymer materials. High-molecular polymer is a kind of high-molecular material, has the adsorption effect, high polymer protection, can improve the advantages of slurry viscosity (Xu,2004 and Dehghanpour,2001). Some scholars carried out some study on the polymer material fluid loss agent in recent years, these study mainly focused on CMC, HEC, MHEC, CMHEC, starch and its derivatives(Zhang,2005 and Chevron,2009).About PAC (polyanionic cellulose) as drilling mud additives, a few of scholars carried out some relevant work. Plank (1992) applied PAC into ordinary freshwater drilling fluid and analyzed temperature stability of freshwater drilling fluid. Bennion (2000) applied PAC into drilling fluid and analyzed effect of polyanionic cellulose on strata inhibitory. Huang (2011) analyzed effect of PAC on properties of the high-density water-based drilling fluid. Mahto (2004) applied PAC into fresh water and salt-water drilling fluid and analyzed effect of PAC on rheological properties of the drilling fluid. Wang (2008) applied PAC into alkaline drilling fluid to study various performance of drilling fluid. PAC is a renewable resource and has good application prospect (Ankara, 2005). So it is very important to understand the effect of PAC on filtration process of drilling fluid.The test was conducted by changing the content of the PAC in drilling fluid. The object of this paper is to understand effect of polyanionic cellulose on filtration process of the low solid-phase drilling fluid."

Jan 1, 2017

By D. X. Xu

A pump station was constructed at the food of a steep mountain, very close to a riverside. To protect the pump station from being washed out, and to guarantee the stability of the steep hillside behind the pump station and the safety of the foundation pit when the station was built, cast-in-place R.C. diaphragm walls (Fig. 1) were clesigned in front of and on both sides of the pump station. This wall was 130m long, 0.8m wide and 29m deep. The diaphragm walling on both sides of the pump station served to prevent landslides and to fix anchor piles. The 55m long diaphragm walling in front of the pump station served as a temporary shuttering which kept earth and prevented water from permeating when the pump station was under construction. After the pump station project was finished, static blasting method was used to blow up the wall body which was 10m beneath the ground so that the water from the river could come into the pump station. The remaining wall body below this level was kept to prevent soil from being washed out. [ ]

Jan 1, 2010

By Saba Mohan

For the three full-scale pile installations, two different high-energy hydraulic hammers were selected for the installation. However, these hammers may not have sufficient energy to drive these large diameter piles at their ultimate capacity following long-term set-up. Nevertheless, these hammers were selected because, soil plug behavior, the generation of excess pore pressures and remolding of soil during driving were expected to reduce the shaft and end bearing resistance, and therefore reduce the energy required to drive these piles to design penetration. Data collected during continuous installation driving and after a series of re-strikes at different set-up times ranging from 1 to 33 days were used as input data for CAPWAP analyses. These results were used to estimate the soil resistance along the pile length and at the toe of the pile, and the soil pile set-up behavior. Validity of the procedures used to predict the soil resistance to driving and predicted blow counts were verified with the field observed blow counts and the energy that was delivered to the pile. Based on combined CAPWAP analyses, the soil pile set-up with time was predicted.

Jan 1, 2002

By Mauricio Coto

Three bidirectional static load tests (BDSLT) were executed on bored concrete piles, as part of the permanent foundations for two buildings sites located at the Sabana, San Jose, Costa Rica, separated at a relatively short distance of about 1 km. Unit skin friction values obtained for both sites, principally for the “Lahar” layer show that in general, friction pile capacity from the tests is higher than anticipated per static calculations from soil borings geotechnical parameters correlations. Results from the tests were also compared with dynamic load tests (DLT) executed at other two sites in the surrounding area, and with a Finite Element (FE) Analysis that model soil-pile interaction for one of the projects. On the other side, some construction issues were detected on one of the sites, which negatively affected the end bearing capacity, but being that pile friction was higher than anticipated, the required overall pile capacity was accomplished. The BDSLTs results of these tests help to better understand the geotechnical behavior of the soil layers in the Sabana. Moreover, they also show that is possible to optimize the design and construction of other bored pile supported buildings and structures on the zone.

By Takeru Fukaya, Tsutomu Namikawa

"The bending tensile stress occurs in the ground improvements when external forces are applied to the column and wall shaped ground improvements. Therefore, in the design of the column and wall shaped ground improvements, the tensile properties of the cement-treated soils become a predominant factor when the external forces induce bending moments. Then the tensile properties are required to design the ground improvements rationally.Three points bending tests are conducted to investigate the bending tensile properties of cement-treated soils in this study. Cement-treated soils mixed in a laboratory are used in the bending tests. The test specimens are prepared with the several mixing properties to study the relationship between the tensile properties and unconfined compressive strength qu. Bending tensile strength Tfb and fracture energy Gf of the cement-treated soils are evaluated from the load-deflection curves obtained from the bending tests. The experimental results indicate that Tfb and Gf are approximately proportional to qu.INTRODUCTIONThe ground improvement by deep mixing has been widely used for structure foundations, retaining walls and liquefaction mitigations. Recently column and wall shaped ground improvements by deep mixing method have been applied for economical reason. When external forces are applied to the column and wall shaped ground improvements, the bending tensile stress occurs in the ground improvements. Therefore, in the design of the column and wall shaped ground improvements, the tensile properties of the cement-treated soils become a predominant factor when the external forces induce bending moments. Then the tensile properties are required to design the ground improvements appropriately.Namikawa et al. (2007) conducted the finite element analysis to investigate the dynamic behavior of the lattice-shaped improved ground for liquefaction mitigation. In the analysis, an improved ground consisting of several grids in a line was chosen to study the basic behavior of the lattice-shaped improved ground. Fig. 1 shows a example of calculated tensile failure zones in the improved soil during the earthquake. Half of one section of the improved soil consisting of two grids in a line for the 8 m × 8 m grid was modeled in the case. In Fig. 1, the failure occurs at the bottom and upper corners of the improved soil grid. The analysis result indicates that the constitutive model which can appropriately evaluate tensile failure behavior of cement-treated soils is required to evaluate the performance of the lattice-shaped improved ground for liquefaction mitigation. In the analysis, the elasto-plastic model developed by Namikawa and Mihira (2007) was adopted for the cement-treated soil behavior. The elasto-plastic model can suitably describe the tensile failure behavior of cement-treated soils. In the elasto-plastic model, tensile fracture energy is adopted to determine a tensile softening relationship because it is difficult to directly measure the stress-strain relationship after the peak stress state in direct tension tests. However there is little experimental study on the tensile fracture energy of cement-treated soils."

Jan 1, 2015

By Jon E. Bischoff

Construction of a secondary clarifier on the banks of Rainy River, Northern Minnesota, required the driving of H-piles 14HP102 to a sloping, very strong bedrock through thick deposits of soft and medium stiff soils. Pile toe protection, APF Hardbite HP 77750, was specified to prevent damage to the pile toe and to enable the pile toe to bite into the bedrock surface. The toe protection worked well for bedrock sloping less than 2H:1V. However, where the bedrock was steeper, the piles experienced damage and failed to reach bearing. In most cases, the also the replacement pile failed. Pile Driving Analyzer measurements showed that on encountering the bedrock, the pile toe reflection, which at first was sound, deteriorated indicating pile toe damage. Extraction for visual inspection showed that the failed piles were bent and had deformed pile shoes. In areas of steeply sloping bedrock and for replacement piles, an alternative shoe, the Scanpile Herkules rock shoe, was employed. This pile shoe proved to be able to secure the pile toe into the rock and to eliminate the problem. The costs of the Herkules rock shoe considering price, shipping, and attaching, were about equal with the Hardbite shoe.

Jan 1, 1993

By Bryan Bet

Retaining wall systems of soldier pile ground anchors (SPGAs) have been used for many decades to stabilize landslide activity. Due to successful use of these walls to address slope instability on the California state highway system, their use has expanded to include larger, more complex landslide mitigations. The increase in size and scope of SPGA wall applications, combined with more stringent seismic design standards, have created new and unique challenges for design and construction. Constructability issues are revealing themselves in real time in Northern California, where the California Department of Transportation (Caltrans) recently completed two large SPGA wall projects on state highways: the Peregrine Slide Project in inland Mendocino County, and the Westport Slide Complex located along coastal Highway 1. Each presented unique construction challenges that needed to be overcome quickly to make the projects successful. This article highlights some construction difficulties encountered on these projects, in greater depth, than what I covered last summer at DFI's S3: Slopes, Slides and Stabiliza- tion conference in San Francisco. Also covered are what steps were taken to overcome these difficulties, and mitigation advice for future wall designs. Specifically, ground anchor installation interference, ground anchor elongation variance, and difficulties with large diameter ground anchor drilled holes will be discussed.

Jul 1, 2022