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By Joe Harris

Large structures, such as a multistory office building or a large storage tank, are constructed the most economical way possible, which may involve a shallow foundation system placed on native soil or compacted fill material. Over the life of the structure, the foundation system may not perform as originally anticipated, leading to differential settlement. Minor differ- ential settlement is expected; however, settlement that exceeds allotted tolerance can render the structure inoperable. Compaction grouting is a well-known and accepted ground improvement technique that can be used to not only stabilize but relevel multistory buildings and large dia- meter storage tanks. Two projects, each with differing types of structures, were successfully remediated utilizing com- paction grouting as the primary method to remedy settlement.

Sep 1, 2023

By Derrick Dasenbrock

Two DFI committees independently organized two complimentary panel sessions for the recent American Society of Civil Engineers' (ASCE) Geo- Risk 2023 "Advances in Theory and Innovation in Practice" Conference in Arlington, Virginia, July 23-26. The Geo- Institute (GI) specialty conference welcomed more than 200 professionals and students interested in risk from around the world to the Washington, D.C., area for three full days of plenary keynote lectures, papers and no-paper sessions. The GI Risk Assessment and Management Technical Committee organized the event, which is the third in a series planned on a 6-year cycle. The previous two events were in 2011 in Atlanta and 2017 in Denver.

Sep 1, 2023

By Osvaldo Valdez, Matteo Bertoni, Aem Ragy

The East St. Louis Deep Cutoff Wall project is located in the area of East St. Louis, Illinois, across the Mississippi River from the city of St. Louis, Missouri, along the left descending bank of the river. The project is a fundamental part of the U.S. Army Corps of Engineers' (USACE) effort to rehabilitate and secure the aging East St. Louis levee system that provides flood protection to approxi- mately 250,000 residents and more than $4.5 billion in economic value. The project was devised and de- signed by USACE as a cutoff wall to be installed in the Metro East Sanitary District levee segment, one of the levee segments that form the East St. Louis system. The contract for the construc- tion of the cutoff wall was awarded in November 2019 to Bauer Foundation, the American subsidiary of the Bauer Group.

Sep 1, 2023

By Jonathan Ernst

The Bruce Museum is an art, science and natural history museum in Green- wich, Connecticut. The museum was originally built as a private residence in 1853, and has undergone several reno- vations, the most recent dating to 1992. The current renovation is part of a $60 million capital expansion plan for the "New Bruce." The renovation includes a 43,000 sf (4,000 m2), three-story addition that will more than double the size of the museum, adding space for new ex- hibitions, education and community spaces. The proposed bottom of the foundations for the renovation sit up to 16 ft (5 m) below the Bruce Museum's existing shallow foundations.

Aug 1, 2023

By Brian McGlynn

There are many factors that can result in a site characterization being limited. For example, a client may undervalue the importance of a good geotechnical report, or an owner may feel that it would take too much time to perform an appropriate investigation among other reasons. For this project, neither was the case. The challenge was that the construction sequence of work required wick drains to accelerate the settlement of soil that had yet to be placed, resulting in the need to create a wick drain bid package based on unknown settlement parameters. This wick drain project took place in Long Beach, California, at the Long Beach Middle Harbor Re- development. For much of the past decade, the Port of Long Beach undertook a $1.5 billion redevelopment of two outdated terminals to create the Long Beach Container Terminal (LBCT). To achieve this goal, the existing terminals were demolished and the slip that serviced one of the older terminals was designed to be infilled to create the new area that would allow for the LBCT to manage 3.3 million TEUS (a commonly used freight term meaning twenty-foot equivalent unit) of cargo each year. Ultimately, the construction of the LBCT would be performed under multiple contracts to allow the new terminal to begin operation in a phased approach. Menard performed the wick drain installation under two out of three contracts, and this case history focuses on the challenges anticipated and faced under the second of these awarded contracts.

May 1, 2023

By Jesus Gomez, Mary Nodine

Rigid inclusions are widely used in the U.S. as a ground improvement tech- nique, particularly for industrial, low- rise and highway applications with poor subsurface conditions, where control of settlement is necessary. Rigid inclu- sions consist of grouted or concrete elements typically 12-24 in (305-610 mm) in diameter that may or may not be reinforced with a center bar. Typical soil conditions where rigid inclusions are feasible might consist of a surface layer of fill and natural, granular soil, followed by a stratum of soft silt or clay overlying a dense or stiff formation. Rigid inclusions are installed from the existing ground surface or suitable work platform, through the surface soils and through the soft, compressible layer, and into the deeper layer, which is less susceptible to compression- induced settlement. Typically, when used to support an extended area surcharge, the inclusions are installed in a rectangular or triangular pattern at regular spacings ranging from 5-12 ft (1.54 m), depending on a variety of factors. The rigid inclusion system is often capped with a load transfer platform (LTP), whose function is to direct a significant portion of the applied load toward the rigid inclu- sions. Additional load is transferred to the rigid inclusions through the upper fill soils above the compressible layer. The rigid inclusions transfer the applied load axially to their tips and into the deeper layer. In the U.S., rigid inclusions are mostly installed using displacement auger systems. The use of a dis- placement auger has significant advantages. It produces zero to near- zero spoils, which is an important environmental consideration. The

May 1, 2023

By Morgan NeSmith

The Port of Palm Beach is a full-service landlord port in Riviera Beach, Florida. The port and its tenants process more than $14 billion in commodities. About 80% of these are exports, which makes the Port of Palm Beach one of only 16 "Export Ports" in the U.S. More than 2.5 million tons of cargo move through the port every year. Ozinga, a fourth-generation family- owned construction materials company, has supplied ready-mix concrete for commercial, residential, public works, landscaping and excavation projects from several of its Florida locations. It planned to build a one-of-a-kind cement storage facility to receive and store international ship- ments of cement for transport to other facilities for the production of ready- mix concrete. Dome Technology, of Idaho Falls, Idaho, designed and constructed the 125 ft (38 m) diameter storage facility. The design and working volume of cement for the facility was just under 27,000 cu ft (765 m3). The design loads required to be supported by the foundation system are shown in this table:

Apr 1, 2023

By Richard Shea

Morris-Shea, an Alabama-based deep foundation contractor, is installing foundation piles at the sites of North America's two largest liquefied natural gas (LNG) terminals currently under construction. The contractor has crews working at Venture Global's LNG lique- faction plant in Plaquemines Parish, Louisiana, as well as constructing foundations for the Cheniere Energy Stage 3 Liquefaction Project in Corpus Christi, Texas. This work includes installing ap- proximately 27,000 DeWaal drilled, full displacement, cast-in-place concrete piles to support seven new midscale LNG trains at Cheniere's Texas ter- minal. Deep foundation installation began at Venture Global's Plaquemines facility, located approximately 30 mi (50 km) south of New Orleans, with an initial phase of 24,000 piles. Plans for the Plaquemines LNG terminal include three loading berths on the Mississippi River and four LNG containment tanks. The facility will utilize new pretreatment com- pressors, liquefaction trains and on- site gas turbine power plants to maintain an annual LNG export capacity of nearly 20 million tons (18 million tonnes) per annum. The site's LNG trains are configured in 18 blocks. The contractor is installing piles through an initial 6-20 ft (1.8-6 m) of cement mixed improved soils, which provide a safe work plat- form for equipment to operate on the extremely weak native soils. Drilling continues through soft clay in the subsurface and tips into a stiff clay or dense sand layer. Production piles are drilled to depths up to 124 ft (38 m) below ground surface. The firm is working with engi- neering, procurement and construction contractor KZJV, a Kellogg Brown & Root and Zachry joint venture, at the Louisi- ana location. The foundation team mobilized at the Plaquemines site in May 2022, to install 16, 18 and 24 in (400, 450 and 600 mm) diameter test piles to depths of 90 and 120 ft (27 and 36 m). The piling contractor returned in September 2022, to start Phase 1 of the deep foundation project, beginning installation of production piles.

Apr 1, 2023

By Shawna Munn, Sarah Speir

Cedarvale Station is one of 25 new Eglinton Crosstown light rail transit (ECLRT) stations along Eglinton Avenue in Toronto. It is an interchange station with the existing Toronto Transit Com- mission (TTC) University subway line and is located at the intersection of two major thoroughfares. The new LRT tunnels run below the existing Yonge Spadina subway line and required total excavation depths of 20 m (65 ft) to facili- tate construction of the new station.

Jan 1, 2023

By Henry Zhang

This paper presents two case studies of large diameter driven tubular steel piles for the ongoing Woolgoolga to Ballina Pacific Highway upgrade (W2B). This project forms part of Australia’s largest regional infrastructure project and will upgrade about 155 kilometers of highway to four-lane, divided road. There are more than 170 bridges on W2B, and driven tubular steel piles are adopted on 43 bridges between Glenugie and Ballina. Driven piles terminating in soil or basalt is a big challenge faced by both designers and piling contractors due to 1) the uncertainty of expected pile unit shaft and base resistance in different soils; 2) whether plugging is formed; and 3) highly variable basalt strength and thickness near top of the rock. If these risks are not adequately managed during design or construction stages, it could lead to unexpected project delay, extra time and cost or pile toe damage in basalt. This paper describes two case studies, one for piles designed to terminate in soils and the other for piles designed to terminate in basalt. How these risks were assessed and managed during detailed design, procurement, hammer selection, pile installation and verification will be discussed in details with lessons learnt summerised in the conclusion.

Nov 1, 2022

By Sameh M. Khella

This paper discusses the application of deep CFA piles for the foundation of structures in different ground stratifications with a focus on the application in Queensland region. Design, construction techniques and quality measures implemented during these procedures are described. Testing methods and verification of capacity, integrity and performance of these piles are also demonstrated. Case studies for this application are presented with an appreciation of this solution within the provided project conditions of each case. Examples of successes and challenges encountered over the course of application of deep CFA in Queensland are mentioned. Limitations of the technique and less favourable situations for its implementation are also highlighted.

Nov 1, 2022

By Muttharam M, Karthick Kumar V

Helical piles foundation systems have been extensively used in engineering application. It is commonly adopted to resist the compression, uplift force, overturning moment and lateral forces. Helical pile system is extensively used in many structures such as Transmission towers, Wind farms and other offshore structure because it is easy and quick to install. Realizing the importance of helical pile, an attempt is made in the present investigation to bring out the effect of spacing between the helix, blade thickness, and shaft thickness through numerical analysis. To validate the finite element model experimental investigation was carried out. In this investigation model steel piles with dual helical plate embedded in clay bed with the consistency of 0.4 was tested to study the effect of uplift loading on the behaviour of piles in tensions. Model helical pile with 12.5 mm diameter circular shaft and helix diameter of 25 mm. The model pile embedded in clay bed for a depth of 400 mm. Parametric analysis of helical pile by varying blade thickness, shaft thickness, and the spacing of helix was carried out by using Finite Element tool Plaxis 3D. From this analysis, an increase in thickness from 4 mm to 10mm increase the uplift load. Similarly, an increase in spacing of helices from 0.5 m to 1.5m increase the uplift capacity beyond that it decreases the uplift capacity. By keeping the contact area of the helix as constant as the number of a helix and helical spacing was varied, the critical number of the helix was found as 2 and the critical spacing of helix was found as 1.5 m for this study.

Nov 1, 2022

By Stephen Buttling

The construction of a water treatment plant in Dandenong, Victoria, required detention tanks and a pumping well. The design provided by the Engineer used conventional rectangular cast-in-situ reinforced concrete walls within a sheet piled cofferdam. It was decided to construct the tank and shaft using the diaphragm walling technique as an alternative and, for the shaft in particular, this involved a “circular wall”. Except where cutters are used, joints in diaphragm walls have to be made between colinear panels, with waterproofing provided by dumb-bell water stops held within trapezoidal forms. This means that the circle has to be approximated by a number of straight sides, which in this case was twelve. The requirement was to design the reinforcement for the strange shaped panels. Finite element analysis was used, in the first stage using an axisymmetric model to determine the profile of lateral earth pressures with depth. In the second stage a horizontal slice was modelled, without gravity which normally operates from the top to the bottom of the page. By considering appropriate possible earth pressures at different depths, a range of bending moments was calculated, which was used by the structural engineers to design the rebar. The tanks were successfully constructed, and inclinometers were installed in both the tank and the shaft. Measured deflection profiles show that the design was moderately conservative.

Nov 1, 2022

By Kishore Kumar B., Eswaran Prasad C R, Srini Naik B., Ramakrishna Raju N

The authors through this paper intend to introduce the non-vibro technique of ground improvement by stone column, being used for the first time in India under the Western Dedicated freight Corridor in Mumbai area. New 2x25 KV double line dedicated freight corridor tracks, capable of carrying 32.5-ton axle load are proposed to be built on this stretch. Non-Vibro Displacement Stone Columns of 900 mm diameter were installed to improve the safe bearing capacity of the soft ground to take the loading of Dedicated Freight Corridor Railway embankment. Vertical footing load tests on single and three column groups were conducted to assess the improvement in the sub-surface condition after installation of stone columns. This paper describes load tests conducted on stone columns and analysis of the obtained results. The observed load settlement behaviour of the improved ground has also been presented. Behaviour of single and group of stone columns have been compared and criteria adopted for arriving at desired factor of safety based on the settlement observed, has also been discussed.

Nov 1, 2022

By Leong, William. Chong, Kam Weng

Deep Vibro Techniques namely Vibro Compaction (VC) and Vibro Replacement (VR) are widely used in ground improvement to densify sands and strengthen cohesive soils. This paper describes the application of these techniques for the construction of 20 Ha Iron Ore Stockpile Yard with the maximum stockpile height of 14 m in Quang Ngai, Vietnam. The challenges of this project are to limit the stockpile allowable settlement and the surrounding pile’s lateral movement. The soil condition can be summarized as 12m – 18m thick of loose to medium dense SAND with qc around 5-18MPa and followed by 2.0 – 6.0 m thick soft clay with qc around 0.4 – 0.8MPa. Localized very dense sand layer was found. VR using stone columns were installed in soft clay layer while VC was adopted to densify sand layer. Additional shallow stone columns were built in sand strata to minimize pile top lateral movement. The post construction performance was verified by a large 6 m by 12 m plate load test (PLT). The predicted PLT deformation using Priebe’s improved properties for the VR will be presented and compared with the measured plate load test results.

Nov 1, 2022

By Tian Miaomiao, Cheng Yin, Shen Jun, Yu Hao, Li Yafei

Vast amounts of waste drilling mud containing heavy metals is produced during oil drilling process, which causes great pollution to the environment. Therefore, it needs to be treated until it is harmless. This study uses industrial waste and Portland Cement stabilized waste drilling mud; the unconfined compression strength, leaching amount of Pb2+ and Cr6+ ions, and pore size of the stabilized soil were tested at different times during freezing-thawing cycles. The antifreeze performance of the stabilized drilling mud with industrial waste is discussed. The results show that the strength of the stabilized soil decreases with an increase in the number of freeze–thaw cycles. The strength loss of the stabilized soil after freeze–thaw cycles can be effectively reduced by increasing the industrial waste content, especially the content of phosphogypsum in the stabilizer component. Pb2+ ions and Cr6+ ions can be effectively stabilized by industrial waste. The results of the pores test prove that the compactness of stabilized soil solidified by industrial waste residue is greater than that of cement alone.

Nov 1, 2022

By Chris Leach, Lucie Spencer

This case study describes the geotechnical aspects of the basement construction for a multi-storey, residential and hotel complex located in the newly developed Elizabeth Quay precinct in Perth, Western Australia. The development included a three-level basement for car parking covering the full site area which was constructed using the top-down construction sequence. Soil conditions generally comprised 2m of fill overlying medium to dense clayey sands that in turn were generally overlying a very stiff clay stratum at approximately 13m depth. Bedrock level was generally encountered at approximately 22m to 35m below ground level. The ground water table was at a depth of approximately 1m below the existing ground surface level. A site boundary basement wall was constructed using a diaphragm wall retention system. The majority of the vertical loads from the building were transferred to the Kings Park Formation (KPF) bedrock through the use of foundation piles constructed by the CFA method. The CFA piles were installed from existing ground level, resulting in approximately 9m sacrificial concrete length from pile platform level to basement 3 (B3) level. The permanent column loads are such that a single CFA pile was not structurally adequate. To allow a full CFA foundation system to be adopted, an innovative design and construction approach was developed for these heavily loaded columns. This paper discusses the site technical details and the design and construction aspects required to meet the challenges offered by this project.

Nov 1, 2022

By Nagarajan. D, Raja Rajan. K, Vijayakumar. T

Major bridges crossing mighty rivers must be constructed in flowing water. Constructing the sub-structure in water has been a challenging job for contractor. Special construction techniques with marine fleets to be adopted for waterfront construction. Enabling works like temporary piling platform and cofferdam used for pile and pile cap construction. Apart from this, enabling works like load out jetty to transport the materials from land to water; temporary walkway for access of workman to work location; temporary access bridge for construction vehicles movement; temporary liners for tower crane foundation; Concrete block to act as dead man anchor for barge movements were all required by the contractor for smooth functioning of site as per construction schedule. Investment in enabling works by contractor plays a significant role on profit margin of the project and of course with utmost safety. Design of enabling works for waterfront structures involves hydrological data like afflux, bathymetry survey, current force, scour depth and wave force to be taken cautiously for safe and economic design. Type of foundation and pile/well cap top level corresponding to water levels shall influence the construction scheme. Usage of geotechnical software like Wallap and Plaxis required for enabling work design to enhance the safety of the structure. Bathymetry and soil condition play a critical role in design and construction of enabling works. Water Discharge quantity in river along with water levels like low water level, high flood level, seasonal fluctuation of water levels has a great impact on design of enabling works. Establishing enabling works for waterfront construction near to an existing bridge is an additional challenge for the contractor. Along with design, constructing the enabling works in water requires special construction methodology and sequence of work. This paper shall provide insights on overview of design and construction of enabling works for waterfront construction.

Nov 1, 2022

By Carlandrea Albonico, Salvatore Miranda

After a brief introduction of the whole Project, the paper describes two special geotechnical engineering solutions provided within the scope of the Galataport Project, in Istanbul, Turkey. The first refers to the new quay of Salıpazarı, which is a combination of retaining structure and ground improvement, formed by a combiwall, a reinforced concrete diaphragm wall and a soil improvement by deep soil mixing (Turbojet). The second, refers to the soil improvement works executed underneath three existing buildings. Single-fluid jet grouting columns had the scope of improving the mechanical properties of the bearing soil and reducing the associated risk of liquefaction. A set of underpinning micropiles was installed in order to allow the excavation of a partial basement inside two of these three buildings. All activities were conducted from inside the existing buildings, with reduced headroom. The paper highlights the importance of employing cutting-edge technologies within the foundation engineering field and state-of-the-art electronic control devices, in parallel with the essential human expertise, in order to obtain the desired results in this high-profile Project.

Nov 1, 2022

By Lee R. Buhagiar

As a result of the increased seismic risk and the highly variable geology of Christchurch, finding costeffective foundation solutions has been a challenge for the Canterbury rebuild. The soil profile in Christchurch comprises both terrestrial (Springston Formation) and marine (Christchurch Formation) alluvial deposits with a high groundwater table. The result is a highly variable and interbedded soil profile which is prone to liquefaction and static settlement. Vibro-replacement stone columns are very effective in mitigating liquefaction in clean sand. However, the author’s experience has shown that vibro-replacement stone columns are also effective for treating silty and soft soil layers. Vibroreplacement stone columns can be used to treat these soft soils by increasing the composite soil stiffness and providing a load transfer path to the underlying dense soils. Another challenge encountered in the Canterbury rebuild is the cost of redevelopment of brownfield sites with contaminated fill. The costs of disposing this fill often make projects too expensive. Vibro-replacement stone columns have been used successfully to treat contaminated fill, providing a treated soil profile with uniform performance and reducing the cost of disposing of contaminated fill. This paper looks at several case studies in Christchurch, with highly variable soil profiles, where vibro-replacement stone columns have been used successfully to treat multiple soil layers, from contaminated fill to silty soils and soft and non-liquefiable silt.

Nov 1, 2022