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It is my great pleasure as mayor of the city of Amsterdam to welcome you today to Amsterdam, and to the 10th International Conference on Piling and Deep Foundations. The history of Amsterdam has been connected intimately with your professions of geo-engineering and geotechnology, since its very first days. It is good to be aware that you are part of a very old tradition. The knowledge that we need today to build and renew the city has been gathered over a century long process so that we fortunately can stand on the shoulders of the giants before us. During the centuries people living in this part of the Netherlands have always struggled against the water. The same waters that brought the opportunity for a seafaring country to discover the world and to build an empire in the 17th century were a threat to the low lying Netherlands.

Jan 1, 2006

By Shane Baker

Cementation Foundations Skanska Ltd encountered many significant challenges in designing and constructing the foundations for the LNG (Liquefied Natural Gas) tanks and associated structures at the Isle of Grain, Kent, UK. With LNG cargo ship levels fixed by the adjacent English Channel, the platform could not exceed critical thickness in order to achieve final grade level, so a safe and efficient working platform for construction equipment on extremely poor alluvial soils was designed and installed. The detailed pile design also required particular analysis of the pile group behaviour and considered seismic load cases not usually associated with UK pile design. Continuous flight auger (CFA) piles were the chosen foundation solution and design was verified through preliminary and working pile tests both axially and horizontally. Contaminated land and existing foundations from a previous oil terminal meant that removal of spoil was extremely costly so specific measures were taken to minimise the off-site disposal. The management of a package of general Civil Engineering in addition to the piling scope, coupled with an unrelenting production program has forced a raising of the bar for this foundation technique.

Jan 1, 2006

By Robert E. Schock, Eric J. Risberg

"Less than 20,000 years ago, the last of the glaciers retreated from the Chicago region. They left behind sheets of glacial clay till underlain by dense, over-consolidated till (“hardpan”) below which is the limestone bedrock, found about 100 ft (30.5 m) below street level. The most notable feature in this profile is the unusually soft clay till that has historically been called “Chicago Blue Clay.”But the founding fathers of Chicago really didn’t care about what was under the ground. They recognized the importance of the city’s location as a potential trade and transportation hub. With access to the East through the Great Lakes and access to the West through the Mississippi River system, the viability of the city was evident. Chicago’s population grew rapidly. The city continued to grow through the Civil War years, but was dealt a devastating blow in 1871 by the Great Chicago Fire, leaving the city in ruins. The Birth of the SkyscraperAfter the cleanup of the Great Fire came the first real building boom in Chicago’s history. During this era, buildings were generally founded on shallow footings bearing on sand or clay. Many multistory buildings were constructed between 1880 and 1890 on spread footings. The first tall buildings were constructed with load bearing masonry walls. These early tall buildings suffered significant settlement as the soft clay underwent consolidation.The Home Insurance Building, built in 1885, was 12-stories tall and is generally acknowledged to be the first “skyscraper” in the U.S. It was the first building constructed with an iron skeleton frame instead of load bearing masonry walls. Spread footings were used under the interior columns in an effort to better distribute the loads, but the building still experienced large settlements.Construction began for the Monadnock Building in 1891. The 17-story building was built using load bearing walls 7 ft (2.1 m) thick, supported on rail-grillage footing foundations. When completed in 1893, the Monadnock Building boasted the title “World’s Largest Office Building.” The total building settlement over the past 125 years has been measured at over 20 in (0.51 m). The engineering community in the late 19th century observed settlement, but did not yet understand the process of consolidation of the soft clay beneath the city. During this time, many of the new buildings required structural repairs during and after construction; the problem was especially acute in buildings where highrise towers joined lower podium structures."

Jan 1, 2016

By Vijay Kumar, Serhat Baycan, Karsten Beckhans

For the deep foundation of podium and tower of the Kuala Lumpur City Centre, BAUER (MALAYSIA) SDN. BHD. constructed 225 bored piles with diameter range of 2.0 to 2.5 m. In order to comply with the depth requirement of the design, for planning purposes and preparation for site, the drilling equipment was required to achieve a maximum drilling depth of 150 m. Actual piles constructed on site were deeper than 120 m. These dimensions caused superlative challenges which included but were not limited to; controlling the open hole stability over time with polymer, installing 70-ton heavy steel cages, pouring up to 550 m³ concrete continuously, in conjunction with installation of kingposts into workable, fresh concrete. The piling works were executed with a BG 72, the biggest drilling rig globally available, and the stringent verticality of the pile bore holes which required approval prior to cage installation. For verification of verticality, Bauer’s patented Drilling Inclination System was successfully used.

Nov 1, 2022

By Daniel Stevenson, Richard Guenther

"The preservation of historic buildings is not only essential to the understanding of our national heritage, but it is also environmentally responsible to adapt existing buildings to compatible new uses. With this perspective, the American Enterprise Institute began exploring options to expand the newly acquired Andrew Mellon Building, located at 1785 Massachusetts Ave. NW in Washington, D.C., without causing any harm to the Beaux Arts style limestone façade and its plaster interiors. The building is a National Historical Landmark, but its 72,000 sq ft (6,690 sq m) of usable floor space did not meet the needs of its new owner. The building perimeter is very near the property line, so horizontal expansion was not possible. Adding height to the building was not an option, as this would have altered the historic nature of the building exterior. The only feasible option that could provide the desired floor space was to add a new floor underneath the existing structure. By adding a level beneath the existing building, an additional 28,000 sq ft (2,601 sq m) of floor space could be produced.Berkel & Company Contractors was chosen as the deep foundation/shoring contractor tasked with ensuring that the existing structure was stable and remained undamaged during the excavation and construction of the new lower level. To accomplish this, Berkel provided a shoring system that would act as both excavation support and permanent deep foundation elements for the final structure.Preservation of the existing limestone façade and plaster interiors was critical to the success of the project, as additional foundation settlements could damage these irreplaceable building components. Project specifications, therefore, included very stringent limits for foundation settlements. The maximum allowable total settlement for all existing building walls and columns was ¼ in (6 mm) for the duration of the project."

Jan 1, 2017

By Tae Hwan Lee, Jun-Shin Lee, Daejin Kwag, Sangchul Bang, Gerard T. Houlahan, Moo Sung Ryu

"Geotechnical engineers have been installing innovative, permanent underwater foundation systems utilizing suction buckets for the offshore industry since the early 1980s (Senpere and Auvergne, 1982). This foundation system has been successfully used on numerous and various types of offshore structures in a wide range of environments. Suction buckets have numerous advantages compared to conventional underwater foundation systems. The more notable advantages include easy installation, large loading capacity, low noise and retrievability. The application of reduced water pressure inside the bucket facilitates the installation of the suction buckets, where a suction pump attached at the top of the bucket can accomplish the entire driving operation. Because of this efficient operation, very large suction buckets can be driven into the seafloor, which eliminates the use of a large number of small piles.In Korea, one of the most economical and reliable renewable energy sources is wind power; however, onshore wind power generation has encountered many problems, such as the lack of favorable sites and public concerns about noise and environmental damage. Consequently, offshore wind power generation has attracted increasing attention due to its abundant potential, high efficiency of grid connection, and availability of easy expansion.In November 2011, the government of Korea announced a national offshore wind power development roadmap, which targeted its offshore wind power generation with the goal of becoming one of the top three nations in the world for offshore wind power generation. Korea Electric Power Corporation Research Institute (KEPRI) is the main research arm of the Korea Electric Power Corporation (KEPCO) and conducts research and development on electricity, power generation, renewable energy and other energy-related matters. KEPRI ultimately provides forefront knowledge and leadership to KEPCO with respect to energy and related areas for its near- and long-term needs. Financial support for the overall project, of which the suction bucket foundation system installed for the pilot phase wind turbine is described below, was provided from the New and Renewable Energy Program of the Korea Institute of Energy Technology Evaluation and Planning funded by the Korean Government Ministry of Trade, Industry and Energy"

Jan 1, 2017

Jan 1, 1998

By Frank Callanan

The Ameristar Casino expansion project included the design and construction of a 25-story hotel and 9-story parking structure expansion. The site is located in a floodplain on the banks of the Missouri River in Saint Charles, Missouri, where the underlying soils are potentially liquefiable. The geotechnical engineer performed subsurface exploration and analysis, which included site-specific seismic response and liquefaction, and provided geotechnical design recommendations. In the event of an earthquake, post-liquefaction settlement was calculated to be approximately 14 inches. Additional project constraints included wetlands protection, construction adjacent to the existing facility, flood protection and river bank stability. Because of the liquefaction issue, the geotechnical engineer consulted with a specialty geotechnical contractor on ground improvement methods. This consultation led to a proposal to eliminate deep foundations from the design and support the structures on shallow and mat foundations. The geotechnical engineer assisted the design team with foundation design analysis and value engineering assessments. Together with the project team, the geotechnical engineer used the data to evaluate foundation options and construction methods to overcome the site challenges and concluded that ground improvement was the optimum course of action. Because of the nature of the site constraints, a number of ground improvement methods were needed. The geotechnical engineer evaluated the methods proposed by the geotechnical contractor and provided the technical specifications for the ground improvement bid package, which included vibro-compaction, compaction grouting and micropiles. The ground improvement allowed for the use of shallow foundations (mat and spread footings), which provided the client with significant time and cost savings over the deep foundation alternatives.

Jan 1, 2009

By Seyyed Mehdi Radeghi Mehrjou

The current work investigates the behavior of inclined micropiles under seismic loads. The dynamic finite element method (FEM) was employed. Rayleigh damping was applied to the soil, and elastic beam elements were employed to model the micropiles. The micropile structure was assumed to have one degree of freedom as a column with concentrated mass. The numerical modeling of micropiles was performed to explore the effects of their inclination on their seismic performance within homogeneous soils with uniform stiffness. In addition, the effect of soil stiffness was studied by considering various stiffness in soil depth. The results from the studies have shown significant effects on the dynamic amplification and internal seismic-induced loads of inclined micropiles.

Sep 1, 2022

By Yahia M. Al-Smadi

Effect of lateral loading against existing sheet pile wall and distribution of gravity loading due to various number of construction loading scenarios were studied. The objective of this effort was to determine the loading case that permits the contractor to utilize a 400 ton crane at the specified location with the existing limitation imposed on site. Staged analysis was determined as the methodology that will more accurately predict the exiting and additional stress due to the impose crane loading. A reliable and robust analysis (ANSYS) software was used to complete both 2D and 3D finite element model and analysis. Analysis model parameters such as material properties, non-linear behavior of the soil, and meshing are presented and discussed. At the conclusion specific range of crane operation and pick weights operating on existing concrete mat supported on top of an existing tunnel was reviewed and deemed acceptable.

Jan 1, 2010

By Joel Moskowitz, George J. Tamaro

"A new office complex is being constructed within 25m of the Hudson River in New Jersey. The project, about 140m by 100m, will include 4 basements under the entire footprint. The perimeter was to be secured by a 0.8m thick diaphragm wall, laterally supported by high capacity tieback anchors to rock. Columns were to be supported on footings or piers to rock at a nominal bearing pressure of 3.8MPa at depths up to 17m. Although some variation in rock quality was observed in borings, a substantial vertical seam of weathered and/or decomposed rock, 1 to 2 meters wide by as much as 8 meters deep, was encountered during construction necessitating field redesign. In some locations, the seam dipped below rock that is more competent. Footings were redesigned for support on drilled caissons, or soft rock was excavated and replaced with concrete necessitating a reduction in bearing pressure of the footings by one half. The tower covering the south half of the site was topped out in 2002 and the garage levels in the north half of the site were completed in 2003.PROJECT DESCRIPTIONIn September 1999, a major investment company began the due diligence process to evaluate a property on the shore of the Hudson River in Jersey City, New Jersey for a new multi-use complex. The site offers a spectacular view of lower Manhattan directly across the river from the site of the former World Trade Center. The site, covering two city blocks, was previously occupied by manufacturing and office facilities of Colgate-Palmolive.The building footprint is approximately 140m by 100m, the southern half of which is occupied by a 260m tall office tower, shown in Fig. 1. As of this writing, design of the structure for the northern half of the site has not been finalized, but it is expected to comprise an 11-story office building. A glass-covered atrium will occupy the street that formerly separated the two blocks. As part of the due diligence process and preliminary design evaluation, alternatives were considered to accommodate various numbers of parking places, both above and below existing grade. A major consideration for below grade parking is the proximity of the Hudson River some 25m east of the east building line."

Jan 1, 2004

By B. De Paoli

At Pietrafitta, between Assisi and Perugia, ENEL (Italian National Electricity Authority) has for some time been managing a power-station operated with lignite, mined from an open mine on the way to exhaustion. A new plant is under construction which is located in the mine that was filled with tailings, mainly clays, sandy silts, lignite and ashes produced by the power-station. The soil profile is shown in Fig. 1: the thickness of the made ground is around 27 m. The foundation of the new power-station is on 320 t piles, 1.20 m diameter, embedded in the cohesive base formation at a depth of 57.5 m. 2,350 piles will be constructed for a total length of 125 km. It is therefore one of the largest pile sites at present in operation in Italy. [ ]

Jan 1, 1994

By Aly M. Mohammad

The Delaware River Tramway will link civic and retail developments in Philadelphia, Pennsylvania and Camden, New Jersey. Twin 300-foot towers will anchor the cables at either side of the river. Four high capacity drilled shafts designed by the Geotechnical Department of DMJM+HARRIS support each of the towers. At the Philadelphia tower, each 6-foot diameter shaft extends 130 feet deep and terminates with a 30-foot rock socket. The shafts are situated within the footprint of an existing relieving platform, which complicates the typical construction sequence. Also, the subsurface conditions at the site provide a unique challenge in both the design and construction of the drilled shafts. During the construction of the four-drilled shafts for the Philadelphia tower, a 6000-ton Osterberg load test was performed on the first shaft to verify design assumption and confirm the shaft capacity. The results of the test were utilized to establish load transfer characteristics and develop foundation design parameters suitable for the site conditions. By doing so the Design Engineer was able to reduce the length of the rock sockets on the remaining production shafts by approximately 5 feet per shaft. As a result, the test provided a significant cost saving to the Owner by eliminating 15 feet of rock drilling from the construction costs. This paper presents a description of the unique design and construction methods adopted for the foundations, also on the Osterberg load test including equipment used, number and locations of strain gages, and interpretation of results. The results and findings presented in this paper could benefit both the design and construction industries because it provides a comparison between geotechnical design assumption and actual field measurements; which has always been a challenge particularly for rock formation.

Jan 1, 2002

By Aly M. Mohammad

The design of large diameter drilled shafts in weathered rock has always presented a challenge to the foundation engineers. Degree of weathering and load transfer mechanism through the rock are essential elements required for the design. From the Contractor's perspective specifying the right equipment and estimating the rate of drilling in the weathered rock are key elements for successful construction. The Delaware River Tramway Project has provided an opportunity to address the design and construction of drilled shafts in weathered rock. The Tramway, supported by twin 300-foot towers, will shuttle eight-person gondolas across the Delaware River in about four minutes. Each tower, founded on four high capacity drilled shafts, is designed to resist large axial and lateral loads. At the New Jersey tower, each 7-foot diameter shaft extends 145 feet deep and terminates in weathered Mica Schist. The shafts are situated in the Delaware River where the mud line is approximately 20 feet below Mean Low Water. Below the mud line, there exists a very soft, 20-foot thick layer of organic silt, followed by a 40-foot thick dense sand stratum. Below these sand and silt strata, a 70-foot thick layer of weathered Mica Schist underlies the entire site. Both skin friction and end bearing in the weathered rock stratum were utilized in the analysis to compute the axial capacity. AASHTO and the PennDOT design methodologies were utilized independently during design of the drilled shafts to verify the design. The drilling of large diameter drilled shafts embedded into weathered rock and situated in a marine environment provided a unique challenge in the construction. A permanent steel casing was installed for a specified depth and proper equipment was used to drill and keep the shaft open through the weathered rock. In addition, a 5000 kip Osterberg load test was performed on one shaft to verify design assumptions and confirm the shaft capacity. The results of the test were utilized to establish load transfer characteristics within the weathered rock and to develop foundation design parameters to be used for the remaining shafts.

Jan 1, 2003

By Gordon] [Reavis

Halliburton Services and Brown & Root have developed a unique foundation system that blends oilfield and construction technologies to construct deep foundations which offer significant advantages across a variety of soil profiles. This highly efficient system is being developed to meet the construction industry's needs into the 21st Century. Based on a concept initially introduced to Halliburton Services by V.L. Schellhorn in 1987, Halliburton combined their existing cement slurry mixing and pumping technology with oilfield drilling practices and a new tool design to field test the viability of the concept. Results looked encouraging, and Halliburton asked it's sister company, Brown & Root to evaluate and further develop the process. With Brown & Root's knowledge of the construction industry, the original concept has developed into a viable and efficient foundation construction system.

Jan 1, 1993

By Serhat Baycan, Mikias Yohannes

"Kuala Lumpur Karst is a complex limestone formation that is characterized by presence of cavities, solution channels, pinnacles and floaters. Basement excavations in such geological formations are usually challenging, mainly owing to the unpredictable rock head depths and potential for groundwater inflow. Any excavation support system should have adequate robustness and water tightness. Traditionally, Secant Bored Pile walls (SBP) with struts are the preferred option for karst ground. This paper discusses a cost effective and innovative alternative solution for a particular site – using Deep Soil Mixing (DSM) and using Contiguous Bored Piles (CBP) together with Ground Anchors (GA). The site, located around one of the busiest areas of Kuala Lumpur, is a 5,700 m2 commercial and residential development. A 16.0 m deep excavation was needed for four levels of basement and excavation support along the 275 m perimeter of the development. Within the site, the depth to rock head varied from 6 m to 19 m. The basis for each solution and conditions for its suitability are discussed in detail. Some design considerations and construction challenges are also presented. The performance of the two retention systems during excavation are presented, together with comparisons versus design predictions. Suggestions for future development are also given. Advantages of this approach compared to other traditional approaches are highlighted.1. INTRODUCTIONThe geology of Kuala Lumpur is among the most complicated and geotechnically challenging formations in South East Asia. The majority of the city falls into the Kuala Lumpur Limestone formation; which is a thick, highly-weathered and cavernous limestone. This formation is pure calcitic to dolomitic in composition, having infrequent schist and phyllite interbedding (Gobbett et al., 1973).The KL limestone has a highly karstic topography dotted with cavities, ravines, interconnected subterranean channels, pinnacles, overhangs, floaters and slump zones (Tan, 2006). This results in erratic bedrock profiles even within short distances. It is not uncommon to see a precipitous rock head incidence within short distances in the same site. In most parts of the City, the bedrock is typically encountered ranging from very shallow depths to about 30.0 m. The exception to this is at the heart of the City, where Kenny Hill formation prevails above the KL limestone. In such cases the limestone bedrock can be encountered much deeper. The erratic rock head profile and the highly karstic nature of the KL limestone makes it a geotechnical challenge requiring careful consideration of suitable engineering solutions.1.1 – Site DescriptionThe site, located in downtown Kuala Lumpur, is abutted by a busy street on the North. Before development, the site previously served as a car park. To the west an access road separates the site from an empty lot; while on the east, the lot is bounded by light weight residential and commercial buildings. On the south side, the site is bordered by a road that separates it from a prominent Shopping Mall in the City. A layout plan and an artist’s impression of the finished development is shown in Figure 1."

Jan 1, 1900

By Karen Dawson

This paper presents a case study of the deformation-based design, construction, and performance of stone column ground improvement (GI) beneath a mechanically stabilized earth (MSE) wall and bridge abutment with heights up to 50 feet. As part of the widening of Interstate 5 (I-5) to allow High Occupancy Vehicle (HOV) lanes in Tacoma, Washington, a new approach and span over the Puyallup River will be constructed. During the soils investigation and design phase of the project, low plasticity silts (ML) inter- bedded with silty sand layers and organic silt where identified as being potentially liquefiable. Stone column ground improvement was designed using a deformation-based approach to address static settlement and seismic stability of the proposed MSE embankments. The deformation-based design of the stone columns resulted in significant savings over a limit equilibrium-based approach. This paper presents the results of sonic coring taken from the initial stone columns installed and compares these results to the real-time data acquisition reports from the stone column installations. Vibration monitoring results during stone column installation are included. Settlement monitoring at the face of the MSE wall and buried vibrating wire settlement monitoring elements are presented and compared to the original settlement predictions.

By Dominic Parmantier, Karen Dawson, Suthan Pooranampillai, Seungcheol Shin

"This paper presents a case study of the deformation-based design, construction, and performance of stone column ground improvement (GI) beneath a mechanically stabilized earth (MSE) wall and bridge abutment with heights up to 50 feet. As part of the widening of Interstate 5 (I-5) to allow High Occupancy Vehicle (HOV) lanes in Tacoma, Washington, a new approach and span over the Puyallup River will be constructed. During the soils investigation and design phase of the project, low plasticity silts (ML) inter- bedded with silty sand layers and organic silt where identified as being potentially liquefiable. Stone column ground improvement was designed using a deformation-based approach to address static settlement and seismic stability of the proposed MSE embankments. The deformation-based design of the stone columns resulted in significant savings over a limit equilibrium-based approach. This paper presents the results of sonic coring taken from the initial stone columns installed and compares these results to the real-time data acquisition reports from the stone column installations. Vibration monitoring results during stone column installation are included. Settlement monitoring at the face of the MSE wall and buried vibrating wire settlement monitoring elements are presented and compared to the original settlement predictions.IntroductionStone column ground improvement was implemented as a means of supporting mechanically stabilized wall approaches for a new bridge over the Puyallup River, part of HOV improvements to I-5 in Tacoma, Washington. The work discussed in this case history was part of the Washington State Department of Transportation (WSDOT) I-5/Portland Avenue to Port of Tacoma Road, Stage 1 Northbound HOV contract, developed as an early work element to a follow-on bridge construction project. The area requiring stone column ground improvement is shown in Figure 1. The improved ground supports permanent geosynthetic walls and embankments up to 50 feet high. This wall can be seen in Figure 1. The selected ground improvement primarily provides global stability of the soils beneath the walls during anticipated seismic loading and also reduces the time and magnitude of consolidation settlement under the weight of the planned embankment.Approximately 74,000 cubic yards of liquefiable alluvial soils were improved by stone columns. Stone column construction occurred in late 2010 and early 2011. This was followed by the embankment and wall construction. Settlement monitoring began with the embankment construction and continued into 2012."

Jan 1, 2017

By Suthan Pooranampillai

This paper presents a case study of the use of single axis cement deep soil mixing (CDSM) to deal with static settlement and seismic stability of the foundation soils under a reinforced soil slope (RSS) embankment up to 50 feet high. As part of the widening of Interstate 5 (I-5) to allow High Occupancy Vehicle (HOV) lanes in Tacoma, Washington, a new approach and span over the Puyallup River will be constructed. During the soils investigation and design phase of the project, low plasticity silts (ML) inter-bedded with silty sand layers and organic silt where identified as being potentially liquefiable. CDSM was selected to address the embankment foundation concerns and allow for future trenchless installation of utility lines beneath the embankment. The presence of a confined, artesian aquifer within the design depth of the CDSM led to the installation of a depressurization system to avoid an upward gradient through the wet soil-cement. In addition to addressing the design approach, the paper discusses the challenges associated with quality assurance of CDSM within the time constraints of an ongoing project. The limited recovery rate of conventional triple tube coring in the soil-cement and double tube wet sampling led to the use of sonic coring to provide a near continuous core of the soil-cement.

By Dominic Parmantier, Karen Dawson, Suthan Pooranampillai, Seungcheol Shin

"This paper presents a case study of the use of single axis cement deep soil mixing (CDSM) to deal with static settlement and seismic stability of the foundation soils under a reinforced soil slope (RSS) embankment up to 50 feet high. As part of the widening of Interstate 5 (I-5) to allow High Occupancy Vehicle (HOV) lanes in Tacoma, Washington, a new approach and span over the Puyallup River will be constructed. During the soils investigation and design phase of the project, low plasticity silts (ML) inter-bedded with silty sand layers and organic silt where identified as being potentially liquefiable. CDSM was selected to address the embankment foundation concerns and allow for future trenchless installation of utility lines beneath the embankment. The presence of a confined, artesian aquifer within the design depth of the CDSM led to the installation of a depressurization system to avoid an upward gradient through the wet soil-cement. In addition to addressing the design approach, the paper discusses the challenges associated with quality assurance of CDSM within the time constraints of an ongoing project. The limited recovery rate of conventional triple tube coring in the soil-cement and double tube wet sampling led to the use of sonic coring to provide a near continuous core of the soil-cement.IntroductionCement deep soil mixing (CDSM) was used as a replacement for stone column ground improvement in a corridor which the owner, the Washington State Department of Transportation (WSDOT) wanted to reserve for future trenchless crossings beneath reinforced soil embankments within a freeway interchange. The work was part of HOV improvements to I-5 in Tacoma, Washington. The CDSM construction occurred in late 2010 and early 2011.Approximately 14,500 cubic yards of soil cement columns were placed by CDSM. The soil cement improved ground supports permanent geosynthetic reinforced slopes up to 50 feet high. The ground improvement was designed primarily to provide global stability of the reinforced slopes during seismic loading, but it was also utilized to reduce the time and total amount of settlement following construction of the embankments.This paper presents a discussion of the design approach and challenges associated with quality assurance of a relatively small volume of CDSM within the time constraints of an ongoing project. The challenges associated with attempts at collecting cores of the cured soil-cement mix cured by triple tube coring and pushing a double tube into the wet mix and allowing it to cure insitu are discussed, along with the eventual adoption of sonic coring combined with reliance on laboratory testing of wet mix samples collected daily."

Jan 1, 2017