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By Maral Papazian Bedian

"Case 2. 100th Street Bus Depot: Elimination of Deep Caissons in Favor of Spread FootingsThe PROJECTThe 100th Street Bus Depot is a new five-story bus terminal for the New York City Metropolitan Transit Authority occupying one city block in Manhattan between 99th and 100th Streets, and between Lexington and Park Avenues. It replaces a former two-story garage, built in the 1890’s and initially used as a trolley-car barn. The new structure is a steelframed building with concrete floors and includes a partial basement near its middle. The easternmost column line with design loads of 10 MN (1,125 tons) is within 1.5 m of the underlying multi-tube Lexington Avenue subway system. To support the new columns along the subway line, the project bid plans had called for 1 m diameter and 17 m deep drilled shafts. The upper 14 m of each unit would have required 50 mm separation from the surrounding rock to prevent stress from being imposed on the roof and walls of the adjacent tunnel. The column loads were thus transferred to below the base of the tunnel and supported by 3 m long sockets in bedrock. The bid documents contained extensive test boring information, which revealed that the project site was underlain by massive Manhattan Mica Schist bedrock within just 3 m below street level. In fact, the Lexington Avenue two-level and multi-tube subway had been tunneled through this rock circa 1910, leaving an about 6 m thick solid roof over the upper-level subway. The NX rock core recovery values were near 100 %, with average RQD of 75 %.The CHANGEThe Bus Depot project was let as a design/build contract with a very aggressive fast-track schedule. Both the pre-bid preliminary design and the subsequent final design by the Contractor’s own hired design engineers relied heavily on very restrictive codes, including unnecessarily conservative approaches to seismic design. Any suggestion for value engineering change was undesirable and was strongly resisted. Yet, objecting against the blind reliance on codes in foundation design, the author questioned the real need for the deep drilled shafts to support the columns along the subway. The unsupported statement that no stresses from the new structure can be imposed on the roof and walls of the adjacent tunnel was not sufficient reason for the drilled-shaft design. Unconvinced that deep shafts were necessary, the author rushed to MTA’s warehouse where many rows of rock core boxes were neatly stacked. Careful inspection and some simple testing of the rock cores with the blows of a geologic hammer gave support to the reservations about the design. Later, as expected, the schist bedrock at this site was found to be hard to very hard with unconfined compressive strength values estimated to range from at least 70 MPa to over 100 MPa (10,000 psi to 15,000 psi). The tensile strength of the rock was assessed to be minimum 5 MPa (750 psi)."

Jan 1, 2003

By Lawrence F. Johnsen, Marc J. Gallagher

"Micropiles are small diameter, bored, grouted-in-place piles incorporating steel casing and/or reinforcements. The omission of micropiles from most United States building codes has resulted in the application of varying standards for design and installation. The ADSC/DFI Micropile Committee has developed a proposed section for the 2006 edition of the International Building Code (IBC 2006) covering micropiles. The proposed IBC 2006 micropile code section is presented, along with comparisons to existing micropile codes and guidelines. A discussion section is provided to clarify sections of the proposed code. IntroductionMicropiles, defined as small diameter (typically less than 12 inches outer diameter), bored, grouted-in-place piles incorporating steel casing and/or reinforcements, are becoming common foundation elements for new construction, retrofits, and emergency repairs. Developed in Europe in the 1950's and used in United States practice since the late 1970's, micropiles are typically not addressed in building codes, particularly in the United States. As a result, micropiles are often reviewed by building officials to a variety of standards, including drilled shafts, caissons, cast-in-place bored piles, and concrete filled pipe piles. None of these adequately address the unique design and construction aspects of micropiles. Therefore, it became apparent to the foundation design and construction community that a micropile-specific code section was required.To that end, the International Association of Foundation Drilling and the Deep Foundations Institute (ADSC/DFI) Micropile Committee appointed a subcommittee in October 2003 to develop and submit a proposed micropile code section for the 2006 IBC. The subcommittee members included the two co-authors, as well as Tom Richards (Nicholson Construction Company), Tom Armour (DBM Contractors, Inc.), John Wolosick (Hayward Baker, Inc.), Allen Cadden (Schnabel Engineering) and Matt Niermann (Schnabel Foundation Company). At the time of the writing of this paper, the proposed code section has been presented at the IBC public hearing during which it was modified slightly. Final adoption (or rejection) will be determined by the IBC at the final action hearing in September 2005. The attached code section is the revised version following the public review hearings."

Jan 1, 2005

By Ramdane Bahar

The new Algiers airport building is a reinforced concrete building of more than 80 thousand square meters of floor slabs. It is located at Dar-EI-Beida, near the old passenger terminal, about 20 km east of Algiers. The project is designed to receive about six millions passengers annually and leaves the possibility of future extension. Due to the presence of a top layer of compressible soil and great concentrated loads transmitted to the foundations, the building is to be founded on 1730 bored piles of 1.2 meter diameter varying in length between 14 and 28 m. Construction work started in 1986 and was interrupted in 1996 due to financial difficulties when the structure was almost complete. The structure was left unattended for more than three years without any weatherproofing and in 1999 a new firm was appointed to complete the work and hence an evaluation of the existing structure was necessary. This paper describes and discusses the foundation design, construction supervision, site quality control and assessment by the parallel seismic method of the deep foundations built in cohesive soils. The variation in soil conditions and identified geotechnical and hydrogeological problems associated with the development of the area, required a thorough knowledge of the soil conditions. A variety of tests, involving more than 200 locations, were carried out. The ground investigation, pile tests as well as different problems encountered during piles construction, are presented.

Jan 1, 2002

By Abolfazl Eslami, Fatemeh Rostami, Sara Heidarie Golafzani, Mohammad Arabameri

Collapsible loess is classified as problematic soil found in most continents. The loess immediately collapses under stresses induced by axial compressive loading or the soil weight when exposed to moisture. In Iran, vast areas of the Golestan province are covered with aeolian loess deposits. This paper investigates whether the simultaneous effect of inundation and pre-loading in helical pile installation are operative and effective in improvement of Golestan loess. The effect of installation conditions on loess collapsibility is studied via two main approaches, i.e., field investigations and physical modelling. The experimental studies include installation of eight single helix piles in the Amirkabir University of Technology Frustum Confining Vessel, i.e., FCV-AUT. Also, four single helix piles with embedment depth of 3 m and diameter of 250 mm were installed in Golestan province and full-scale pile static loading tests were performed. The results indicated that the simultaneous application of crowd loading and water pressure during installation of helical piles results in better soil shear strength parameters. Moreover, high crowd stresses or low crowd stresses accompanied by water pressure during pile installation brings about similar load-displacement behavior of model piles installed in FCV-AUT and full-scale helical piles.

Oct 1, 2022

By Sam Messina

[Project: Job Number: Date: Superintendent: Person Making Inspection: Note: The following checklist shall be used on a regular basis as an overall assessment of the jobsite. The checklist is not all-inclusive. All applicable Federal, State, and local regulations, standards, and ordinances pertinent to the jobsite conditions must be evaluated on a continuous basis. Column A - Adequate Column I ? Inadequate]

Jan 1, 1998

By Timothy Flaherty

We observed the boiling in the water very close to the water adjacent to where we were drilling. That only happened at the very beginning before it was switched to water flushing. Yes, it was performed with water flush.

Feb 10, 2003

By X. M. Wu

The paper describes four different types of support for deep excavations, which are currently used in China. Local experiences were illustrated by presenting case histories for each type of support. For braced excavation in soft clays in Shanghai, the earth pressure against bracings were found to be in conformity with the trapizoidal estimation given by Terzaghi and Peck (1967). For tie-back support of excavations in Beijing and Shengyang, earth pressures were found to be much less than those predicted by ordinary rules. In the construction of a mining shaft in coarse sand below ground water level, high pressure jet grouting has been successfully used to form a circular impervious lining of the shaft. As an effective anti-slide measure, large diameter reinforced concrete piles constructed by open shaft method have been widely used with success.

Jan 1, 2010

By Jeffrey R. Hill

This paper discusses the use of micropiles for the rehabilitation of the following two structures: the Milwaukee Auditorium Theatre, in Milwaukee, Wisconsin, and the Cupples Ballpark Lofts, in St. Louis, Missouri. The paper focuses on the similarities and differences of the remediation techniques used for each structure. The discussion highlights the method of attaching the micropiles to each respective structure. Generally the paper discusses the micropile installation at each project with supporting photos, figures and data. Load testing at each project is also discussed, including the comparison of load test results for each project. The paper will focus on the load testing program at the Milwaukee Auditorium Theatre where high capacity micropiles were designed and tested as friction piles founded in stiff clays and end bearing micropiles in dolomitic limestone. The results of the test were used to determine if the micropiles on the project would be installed as end bearing or friction bearing elements. Strain gauges were used in addition to conventional deflection vs. load data for the Milwaukee Auditorium Theatre project. Other aspects of the paper will include the differences in design methodology for end bearing micropiles in massive dolomitic limestone vs. design in softer, weathered limestone.

Jan 1, 2008

By Sastry Putcha, Santosh Mummaneni, Avasarala Swamy

"Inspection of bored pile hole bottom prior to placement of concrete is one of the most crucial element of foundation design and construction, especially for end bearing piles. Pile hole bottoms that are not cleaned well for sediments could potentially result in settlement. Although many projects have specifications in-place for drilled pile hole inspection, they are rarely implemented as the current available tools are either unsafe or cumbersome and costly, thus making it very unattractive for owners and contractors. Further, sometimes the post-construction nondestructive quality control testing such as PIT or sonic logging on piles resulted in unanswered questions related to soft bottom. This generates costly disputes with additional testing including concrete coring and possible repairs. Currently, there are several bored pile bottom inspection devices in USA, namely, SID, DID, and SQUID which can either provide video and photo documentation or measure sediments.“ShaftCam”, a patented advanced Digital Borescope, was invented to address the issues related to pile hole bottom inspection with its ability to measure sediments as well as photo and video documentation. Shaftcam device consists of 8-inch diameter bell with a camera, led lights, air hose connection and penetrometer with digital measurement that are connected to a control power box and laptop through a cable. The bell is fitted with a round clear open fiberglass skirt to form an open chamber. A simple motorized winch frame allows the user to lower the ShaftCam equipment gently to the bottom of the shaft at the desired location. Once the bell with camera is lowered to the bottom of the hole, air is pumped into the clear chamber to displace the water/slurry/polymer and get a clear view of the hole bottom to record the conditions and measure the sediment thickness and resistance. The skirt can also be enclosed and lowered to the desired location to allow for inspection of shaft walls.ShaftCam weighs less than 15 lbs. (6.8 kgs) in water and allows for inspection of the hole by one person in less than 30 minutes. Use of ShaftCam has saved significant time and money and thus allowed owners and contractors to readily accept and implement the quality control measures in many projects in USA over past few years."

Jan 1, 1900

By R. Chowdhury

The relevance of reliability studies for deep foundations is considered in this paper with special reference to pile foundations. Attention is drawn to uncertainties related to applied loads, the load-carrying capacity and the safety margin of a pile foundation. The essential steps in a reliability study are outlined. An essential goal of any study is the determination of the Reliability Index or Safety Index under different conditions of loading and operation. Calculations concerning probability of failure or success require an assumption to be made concerning the probability distribution of the safety margin. The significance of this and other assumptions should be clearly understood. Reliability approaches should be used to complement conventional deterministic studies.

Jan 1, 2010

By Emre Turk, Suat Gullu, Candan Gokceoglu, Ahmet Sirri, Asli Can

In this study, the ground improvement application applied under the live railway bridge's approach embankments in Sivas, Türkiye was investigated as a case study. The soil profile is mainly composed of orangish conglomerate, clay, silty sandy clay, and under claystone, and mudstone units in the study area. As a soil improvement method, the Deep Soil Mixing (DSM) technique based on the principle of simultaneous mixing the ground while injecting with the water-cement mix, was selected. The application of DSM columns is designed to be 45 degrees horizontal, in order to reach the deepest point of the soft clay units for better improvement against settlement. The core samples were taken from the DSM columns and the compressive strength tests were performed in the laboratory. The results were higher than the minimum designed values. It means that inclined DSM columns were applied successfully, and the excessive settlement problem was solved.

Oct 1, 2022

By Chandramohan P. V

A unique tension pile where the pull is at a point a certain distance below the top of the pile. The pull is transferred by a cable consisting of high tensile strands. The HDPE duct of the cable prevents bond between the strands and pile concrete in upper portion. While soil friction on the pile will act downwards on the whole length, there is tension in the bottom portion of pile, there will be compression at the top portion.

Nov 1, 2022

By Andrew Middleton, Mark Wyatt

"The Brickworks Marketplace Project is a significant shopping centre development in inner north west Adelaide constructed by Badge Constructions in 2014 and 2015. The site was a former brickworks with a deep pit containing various extents of uncontrolled fill which was to remain on site, and with a remaining void up to 6 m in depth. The existing uncontrolled fill was improved using the High Energy Impact Compaction system, and the pit backfilled using a quarry crusher byproduct selected by trial and a recycled crushed concrete and bricks and compacted in deep lifts. This approach resulted in significant savings in compaction time, cost and building foundations. The settlements of various parts of the completed works have been monitored since February 2015 and this monitoring has demonstrated small settlements which meet the user’s constraints.INTRODUCTIONThe Torrensville Brickwork Markets project involved the transformation of a former brickworks and clay pit site into a regional 17,000m2 shopping centre, opening in June 2015.The site was a former brickworks with adjoining clay borrow pit. The clay pit had been partially backfilled over many years with ‘uncontrolled’ fill comprising ‘clean’ soil, bricks and kiln dust typically of the following thicknesses:??of the order of up to 7 m to 10 m but locally up to 15 m in the western part of the site??2 m to 5 m in the south-eastern part of the site; and??less than 0.5 m in the north-eastern part of the siteAnecdotal reports suggested compaction of some of the fill may have been undertaken, although this not able to be confirmed nor records obtained.Initially it was proposed to take up the existing uncontrolled fill, sort and recompact or remove to landfill, followed by backfilling in conventional means over 500,000 cubic metres of imported filling to a thickness of up to approximately 6m to backfill the former pit. This work represented a significant cost and was not economically viable.During early negotiations, the contractor proposed an alternative to retain and ground improve the existing filling on site, and to backfill the pit with fill placed and compacted in deep lifts, thereby significantly improving the economics, environmental and community impacts of the proposed works.The developer agreed to the proposal with the following performance criteria:??a settlement of =10 mm after 10 passes by the Impact Compactor (on existing subgrade areas);??a bearing capacity of 250 kPa for high level footings;??a maximum long term differential settlement of 40 mm (measured over 16 m), ie. 1 in 400; and??a minimum modulus of 40MPa."

Jan 1, 1900

By Sumantra Sengupta

"Northeast Frontier Railway (NF Railway) intends to connect Imphal, the capital of Manipur (bordering Myanmar) with Assam by railway link. They have planned a 125km long railway line that passes through steep rolling hills of Patkai region, eastern trail of Himalaya, and as a result large number of tunnels and bridges need to be designed. While the high mountains are penetrated by tunnel, the deep gorges between the mountain ridges are connected by tall bridges. The tallest of such bridges connects a gorge at about 140m above its bed level with an overall length about 700m at rail level. In all, five such bridges with tall piers are now under construction. With extensive study on possible alternate arrangement of the bridges considering the effect of high seismicity of the area, moderately to highly weathered siltstone/ sandstone as ground bed material, slope of the hills etc it was decided that bridge will be founded on 1.5m diameter bored cast in situ piles with length varying from 20m to 30m depending on the location. The substructures are RCC hollow pier and superstructures are steel open web through type girder of 103.5m span. Considering absence of any major construction work in the vicinity, it was decided that prior to design work, Site-specific spectrum study will be carried out and design will be carried out considering the varying stiffness of the tall piers, each of different height. Interesting results were obtained regarding behavior of piles under lateral loads generated by high seismic conditions. The paper discusses in detail the design of Pile foundations and the effect of bed material along the steep slope on which the piles are being constructed.INTRODUCTIONIndian Railway has undertaken the construction work of connecting the North-Eastern states of India through railway line. The major stretches of the area passes through hilly terrain and as a result the line passes through tunnels and bridges in succession. The tall mountains are being penetrated with tunnels and immediate after deep gorges are crossed with high level bridges. The entire area is under high seismically active zone. The bed material below the ground level of the sloped hill is 4 to 10 meter of mixed soil of sand, gravel, pebbles etc underlain by moderately to highly weathered sandstone, siltstone at the higher level and moderately weathered sandstone, siltstone at lower level. Considering all the aspects like constructability, maintainability, geological and geotechnical aspect, seismicity, stability, safety, functional aspect and cost it was finally decided that the bridges will be simply supported structure with open web through type steel superstructure of maximum span 103.5m and hollow cylindrical discretely varying RCC substructure with 1.5m diameter group of piles as foundation. The paper discusses on the design aspect of the pile foundation in the rocky strata in the hill slope. The codes and standards that have been followed for design are IRS (Indian Railway Standard), IS (Indian Standard), IRC (Indian Road Congress), AREMA (American Railway Engineering and Maintenance-of-way Association), UIC (International Union of Railway) provisions."

Jan 1, 2015

By Paul R. Lear

Sustainability continues to be an important aspect of remediation and infrastructure projects. Deep soil mixing (DSM), a common construction and remedial technology, can easily incorporate the following sustainability best management practices (BMPs), including Minimizing Total Energy Use and Maximizing Use of Renewable Energy; Minimizing Air Pollutants and Greenhouse Gas (GHG) Emissions and Maximizing Use of Machinery Equipped with Advanced Emission; Minimizing Water Use and Impacts to Water Resources; Beneficial Reuse of Materials/Reduction of Materials and Waste Reduction; Use of Local Labor and Supplies. This paper focuses on the sustainability of DSM treatment and provide carbon footprint calculations at least one completed DSM project which used these sustainability BMPs to demonstrate the environmental impact of the sustainability.

Sep 8, 2021

By Emad Farouz, Ehab S. Shatnawi, Charles Winter

The increasing demand for small deformations and high-capacity drilled shafts without enlarging drilled-shaft diameters has motivated the development and increased use of a base grouting (BG) technique. This technique has been demonstrated to improve drilled-shaft axial capacity, especially for shafts tipped into loose cohesionless soils. To date, there are a couple of documented design methods for estimating the axial geotechnical resistance of base-grouted shafts. However, there is no or lack of research that addresses the lateral response of such shafts. A base-grouted drilled shaft test program was carried out during the design phase of the Wisconsin I-94 Zoo Interchange reconstruction project. The test program included installing and testing one base-grouted shaft and one ungrouted shaft under both lateral and axial loading. Based on test results, it was concluded that the lateral behavior of the BG drilled shaft is significantly stiffer than conventional drilled shaft . Hypothetical method was developed to account for potential increased, however, the method should be verified with more lateral load test.

By Jonathan G. Cannon

"This paper will describe dynamic pile testing conducted during installation of driven octagonal precast prestressed concrete piles used as the foundation for this bridge. The piles were long and hence spliced. A number of the piles showed damage near the splices and the damage location was near the ground surface so that the damage could be verified using visual inspection. The piles and splice configuration are still in use today without modification. Further WEAP driveability analysis has been conducted which demonstrates the effect of the splice on pile stresses and a likely failure mode. A slight modification is proposed to the splice that should prevent the damage on future projects.INTRODUCTIONThe bridge site is located on the Olympic Way, Route 41, about 20km north of the regional centre of Albury, NSW. For a long distance north of the site the Olympic Way ""shadows"" the main Melbourne to Sydney rail line and is located on the Western side and in close proximity. At the bridge site there was previously a sharp dog-leg in the road and a right angle level crossing with the road changing to the Eastern side of the rail line, eventually joining up with the Hume Highway, which in turn now becomes a ring-road through the eastern outskirts of Albury. The dog-leg and rail crossing had warning signs and bells, speed restrictions and rumble strips to warn approaching motorists to reduce speed. Site distance was exceptionally good.Approximately 2years before construction a group of five ""high spirited"" young men from the local area were driving south on the Olympic Way adjacent to a south-bound train. It is understood they interacted with the train crew for a period of time. Unfortunately the car and train collided at the level crossing and all of the young men were killed. There were outpourings of grief in the local community and a decision was made to replace the level crossing with a road-over-rail bridge.The bridge was highly skewed with two piers and two high level abutments with fill embankments on both approaches.GROUND CONDITIONSThe site is open grazing country with approximately level ground at the site with surrounding low hills. The geology was unremarkable with consistent stiff clays for a considerable depth.The design required driven precast prestressed pile foundations with the piles to be driven to a considerable depth.Hard driving with high tension stresses were evident from the start of driving and a variety of different pre-bore lengths were adopted in an attempt to minimise driving and potential for damage. At the abutments the pile locations were predrilled for at least the full embankment depth.PILESThe piles were 550mm octagonal prestressed concrete with the pier piles being single piece and the longer abutment piles being two-piece with a ""standard"" epoxy glued box splice. Pier piles and the initial length of the abutment piles were 24m. The add-on piece used at the abutments was 12m. Pile concrete was grade 50MPa."

Jan 1, 1900

By Peter Faust, Peter Hubbard, Kenichi Soga

The European Federation of Foundation Contractors (EFFC) and The Deep Foundations Institute (DFI) have set up a task group to compile a Guide for Working Platforms. The first edition of this Guide has been published in January 2020. The aim of the Guide is to provide reliable methods for design, testing and verification of working platforms for construction equipment, especially in the deep foundation industry where track loads can be excessive due to the nature of its operations. The Guide has identified areas where knowledge is limited. Actual track pressure and its distribution along the length of the tracks is still not well researched. Current recommendation provided in EN 16228-1 are believed to be overly simplified and may lead to conservative requirements for working platform thickness. This paper presents results of a series of field tests where the actual track pressure of a large drilling rig during operation was measured in real time together with the deformation of the working platform. Embedded, distributed fiber optic sensing (DFOS) at different depths throughout the platform allowed for a three-dimensional evaluation of the platform deformation throughout the entire operation. Results will help to develop more reliable recommendations for future safety requirements of working platforms for deep foundation equipment.

May 1, 2022

By Abid Adekunte

"In recent years, developers have had to deal with complexities associated with numerous cases of deep basement construction in built-up areas. Design and construction of deep excavation support systems in urbanised zones come with many technical challenges. Restricted working spaces often render the use of temporary struts as wall restraint systems unpopular, as working space needs to be maximised. Also, tie-back anchors are often inapplicable due to the existence of adjacent structures. Therefore, developing alternative restraint systems for deep basement structures in builtup areas is becoming increasingly important to the present day basement engineer.This paper is centred on the design, construction and monitoring of enabling works for deep basement structures on three sites in the United Kingdom and Republic of Ireland. Traditional tieback anchorage and propping systems were inapplicable on the sites. As alternatives, separate novel wall restraint systems were developed and adopted, to enable excavation on each of the three sites.Performances of the novel wall restraint systems, as well as the responses of adjacent structures were monitored. Numerical modelling and field monitoring results show the three alternative wall restraint systems to be safe and effective. The paper also highlights the advantages of the novel solutions over conventional methods.INTRODUCTIONRecently, deep basement structures have become popular components of urban building developments. As pointed out by Pearlman et al., 2004, this could be attributed to the inadequacy of surface parking spaces in urbanised zones, while underground parking facilities are also believed to improve both aesthetic and commercial qualities of urban structures.However, while the incorporation of basement structure into new urban development appeals to developers and architects, the engineering design and construction aspects of basement works typically come against a whole lot of complexities and challenges. As highlighted by Wong, 2002, engineering problems associated with basement construction in built-up areas are numerous, some of these include; complicated sub-soil conditions, dealing with excessive active pressures, complex temporary works, proximity of sensitive adjacent structures, high level hazards to construction workmen and surrounding community, inadequate working space, etc."

Jan 1, 2015

By Wayne S. Smith, Erik James, Jose R. Gomez

"Soil mixed seepage cutoff walls are increasingly being used in levee and dam modification projects nationwide. An important aspect of their overall quality depends greatly on the language included in the specifications. Depending on the method (e.g. vertical axis auger mixing, cutter soil mixing, or trench mixing techniques) the specifications are a blend of prescriptive and performance based contract language with differences in element construction, element connections, quality control/quality assurance, and work area restrictions. Many of the existing specifications were initially developed by contractors in whole or in part, and can contain restrictive provisions favoring the authoring contractor. In response to these challenges, basic soil mixing fundamentals were revisited and recent lessons learned incorporated, resulting in the development of a new specification for soil mixed seepage cutoff walls that provides adaptability for the various construction methods. The new specification addresses quality control, quality assurance, equipment independence (elimination of restrictive contract language), rig instrumentation.INTRODUCTIONSoil mixing has been used in the construction of seepage barriers for over 30 years. Most soil mixed project primarily use the wet-rotary-shaft, wet-rotary-end or wet-vertical panel methods (reference FHWA Deem Mixing Manual Figure 137). One of the first major soil mixing seepage barriers was constructed in the Jackson Dam in Wyoming. Since then the use of soil mixing for seepage barriers has increased significantly and this specialized domain of construction which was solely procured by RFP methods, is now increasingly being specified in projects issued for bid. The Bid documents require more careful specification writing than RFP methods because the RFP methods allowed detailed proposals by the contractor. Therefore the development of soil mixing specifications began with contractors preparing the specifications. This paper addressed some of these issues, and proposes methods to address these resulting concerns. The resolution of these issues considers several aspects: 1) Assessment of binder injection, 2) Evaluation of mixing index, and 3) Verification testing."

Jan 1, 2016