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By Z. Q. Zhou

It is the first worke in design of pile foundation to determine the carring capacity of single pile, and a static loading on site is considered to be the lost derect and reliable way. All values P and settlements S induced can be plotted as a broken-line. Since soil is a kind of elasto-plastic and cohesive material, the increasing of settlements is generally greater than that of loads. Different value Pu nay be given by different tester on his P-S diagram, because of erroys in the test and complicated, characteristics of soil. The analytical method of exponential equation shown in this paper derives a specified solution. After using an exponential curve to regress values of loads P and corresponding settlements S from on-site test, coeficients A and B of exponential equation can be obtained. With this curve an ultimate carrying capacity of single pile can be determined. The resistant forces of pile shaft and pile tip can also be defined by the tangent of the calculated knee point, as it is called (tangent method). At last, an example is given to show how the ultimate carrying capacity of f 500mm bored pile is obtained with this method for a project in Kunming.

Jan 1, 2010

By Madhav, V., M. R., Ahmad, Padmavathi, M. S.

Modulus of deformation (Es), also referred to as elastic modulus is dependent on many variables such as type of loading, degree of anisotropy and non-homogeneity of strata, etc. and is one of the most challenging soil parameters to estimate. Modulus of deformation of soil can be obtained from elemental tests in the laboratory, from in-situ tests or on the basis of correlations with other soil parameters. Back analysis of full-scale loading test is the most appropriate method for the estimation of the deformation modulus since the effects of installation and pile-soil interactions are accounted for. Moduli of deformation of the ground are estimated from different pile load tests, viz., compression, pull-out, and lateral load tests and compared. The method of interpretation of pile load test is based on the initial liner portion of the load-displacement curve. Theoretical solutions of Poulos and Davis (1980) and Madhav and Poorooshasb (1988) that relate settlement or displacement with load based linear elasticity theory are used. It has been established that the modulus of deformation of the ground is not unique but depends on the type of test and the type of loading. The differences can be significant.

Sep 1, 2022

By Vijaya Bhushan Rao, Jason Redgers

The typical Vibrocompaction projects undertaken in the UAE are on reclaimed Sands. These Sands which are predominantly the crushable, calcareous, carbonate sands found locally as opposed to the more common quartz or silica sands that are featured in most design literature. The famous reclamations such as the iconic Palm Jumeirah in Dubai, often have specification for mitigation of liquefaction induced settlements, bearing capacity increases and total and differential settlement requirements. Often these performance targets are achieved by the means of achieving a particular relative density that are generally measured by a defined Cone Penetration Test, CPT targeting values of cone resistance (Qc), MPa at respective depth zones. In this paper some case studies are presented, where soil suitability for deep compaction by vibratory methods was firstly assessed for suitability using the Massarsch, 1991 compactability chart prior to the application of vibrocompaction and its subsequent evaluation. One such project named the Island Development required 17 to 23m depth of penetration only to treat the lower 5 to 6m of sand above rockhead as eventually the top 15m of sand will be further excavated to allow for the construction of basement. The paper will present pre and post CPT results, the results of initial site calibration trials and evaluation of the completed works.

Oct 1, 2022

By Zaw Zaw Aye, Sereyroath Chea, Nutthapon Thasnanipan, Thayanan Boonyarak

"As there are only limited numbers of bored pile constructed in sandstone and siltstone in Thailand, load transfer and settlement behavior of a pile in these rocks are still not fully understood. Major factors which influence the performance of the pile in the sedimentary rock should be systematically investigated. The objective of this paper is to analyze load distribution and load-settlement behavior of bored pile in sedimentary rock. Interpreted data was obtained from instrumented load testing results of large-diameter bored piles. These piles were drilled in aeolian soil and socketed in sandstone or siltstone, having socketed length varying from 1 to 3 times the pile diameter. Factors that influenced pile settlement behavior, consisting of rock type at the pile base, socket length, at-rest earth pressure and rock conditions, were analyzed. For interpretation of results, analytical solutions were used to estimate load bearing capacity and calculate settlement of each pile. According to test results of mobilized unit skin friction in siltstone, relationship of 0.1 – 0.3 square root of the unconfined compressive strength of rock appears to reasonably capture the measured shaft friction. Note that shaft movement in siltstone layer was not fully mobilized as maximum pile head settlement was still less that 1% of the pile diameter.INTRODUCTIONExtensive research of bored pile construction in soft soil in Thailand and Myanmar (Boonyarak et al., 2016; Aye et al., 2015) has been carried out. However, behavior of bored pile in weak rocks such as sandstone and siltstone is still not fully understood. Unit skin friction and unit end bearing of piles in these weak rock were reported by Horvath et al. (1983) and Pells and Turner (1980), respectively. Further research is still required to minimize variation in data presented in their study.This paper presents interpretation of load testing results of instrumented piles. These piles were excavated in aeolian deposit in the Northeast Thailand. Some piles were socketed in sandstone or siltstone. Analysis results of load-settlement, shaft shortening, pile settlement estimation, factor for calculating shaft friction and end bearing are reported. Discussion and explanation of pile behavior in sandstone and siltstone is provided.BRIEF INFORMATION OF THE PROJECTProject locationsThe construction sites are located in Khon Kaen and Nakhorn Ratchasima Provinces in the Northeast Thailand. Bored piles in this project were designed for supporting elevated structures for railways, overpasses and U-turn bridges for vehicles. These overpasses and U-turn bridges are distributed along the existing railways with the distance of about 180 km."

Jan 1, 1900

By Athena C. Denivo, Pablo V. Lopez, Sissy Nikolaou, Alfred H. Brand, Ahmad Rahimian, Rudivien G. Josef

"The United States Tennis Association (USTA) Billie Jean King National Tennis Center (BJKNTC) site is located in the northeastern portion of the Flushing Meadows Corona Park area of Queens, N.Y. The site occupies some of the most difficult subsurface conditions for construction in the New York City (NYC) metropolitan area, with unique challenges from geotechnical, seismic and foundation design perspectives.At the USTA site, Paleozoic crystalline bedrock is found at a depth of roughly 300 to 400 ft (90 to 120 m) below grade. The geologic history of the site is complicated, starting from the early Pleistocene, when the ancient Hudson River temporarily changed course, flowing across Queens enroute to the Atlantic. It eventually carved a deep valley through the Cretaceous soils, in some places all the way down to bedrock. A series of glaciers advanced and retreated across the region during the Pleistocene times, filling the deep valley with layers of assorted glacial soils. At its southern edge, the last major glacier to flow across the region built up a ridge at the southern tip of Flushing Meadows known as the Harbor Hill terminal moraine. This ridge blocked the valley forming a dam, so as ice started melting away the valley filled up with a lake fed by glacial meltwater. Layers of clean outwash sand and varved silt and clay filled the glacial lake. The ice did not retreat in a steady manner, instead periodically readvancing over the previously deposited soil in the lake, then retreating far enough to let the lake drain temporarily into Long Island Sound, before readvancing again.As a result of this repeated sequence of retreat, advance, retreat, etc., there are places where a “crust” of desiccated soil formed when the lake drained, and areas with interlayers of outwash sand where ice readvanced into the lake. When the ice melted north of Long Island Sound, the glacial lake filling Flushing Meadows drained forming Flushing Creek. During the Holocene (roughly the last 11,000 years), as ice melted further away and sea-level rose, low lying areas filled with river sands and marine clays, along with coastal marsh deposits. Table 1 lists the soil design properties on site and Figure 1 exhibits the geologic section across the site."

Jan 1, 2015

By Peter J. Nicholson

During my more than 40 years in the practice of underground construction and engineering, the industry has seen progress from the dig down to rock or hardpan or alternatively drive concrete or steel into the ground and count the blows; then you can be sure of you have a solid foundation; to the modern day, I?m willing to try anything to save money. Of course these are both exaggerations, but not gross ones. After getting bored being supervision on jobs counting blows, I struck out into the new field of ?tie-backs? as they were called in the United States, or ?ground anchors? as they were then termed in the United Kingdom. After installing some of the first permanent ground anchors for the Corps of Engineers on Lake Michigan as well as the highest loaded rock anchors of the time at two dams on the Ohio River, we were at the top of our game in the 1970?s. Subsequently in the 1980?s when my view of the future of ground anchors saw their installation becoming a commodity item, we branched out into ?Pin Piles? now known as Micro Piles, high capacity, steel tube encased, small diameter (5-12? or so), high capacity (100-500 tons) piling. Next came soil nailing, both temporary and permanent retaining walls, as at Cumberland Gap Kentucky. My next morph was into ?Cement Deep Soil Mixing? earlier on, known simply as ?soil mixing?. For this education I traveled to Japan several times and established a long-term, Joint Venture, relationship with one of the better known Japanese specialty ground modification companies. In Boston at the ?Big Dig? we established the then record size soil mixing project, 500,000 or so cubic meters of CDSM concluding in the year 2000. Since then I?ve been involved as a consultant mainly for dams and levees. Below is the story of how I came to be at this place in the road to innovation in Geotechnical processes.

By A. K. C. Chan

Recent hotel investment projects in China often involve very tight programmes for design and construction. An example given in this paper involves a 24-storey reinforced concrete hotel tower with 460 bedrooms and a 3-level podium commercial complex. The building is supported by relatively widely spaced columns and shear walls below which 88 number large diameter piers were excavated through fill, silty and bouldery clay on to dolerite and slate at depths between 15 to 3 0m below ground level. Whereas much experience has been accumulated in Hong Kong, hand-excavated pier foundation was only adopted for the first time in Dalian. This paper describes and discusses the various factors influencing the choice of the type and design of the foundation system. The criteria for determining appropriate founding levels are then explained. During installation, revisions to the acceptance procedure were made to cater for local conditions. Emphasis is placed on the role of the geotechnical engineer in making on-site decisions during construction. The advantage of the foundation system in accommodating on-site changes resulting from local complex ground conditions is demonstrated. The pier foundations were successfully completed ahead of programme.

Jan 1, 2010

By Joel Moskowitz, Jan Cermak

"New York City has unique geologic conditions which must be considered when designing pile foundations. Where shallow foundations are not feasible, the City's subsurface conditions require a variety of deep foundation systems, ranging from high capacity rock socketed piles, to piles end-bearing on bedrock, to friction piles bearing in alluvial or glacial deposits. Pile load testing is essential in confirming pile capacities as pile analyses include assumptions on soil and soil-pile response, and pile driving equipment. Load test results must be interpreted to estimate the long-term pile behavior. Except for lightly loaded driven piles, the New York City Building Code (the Code) requires that pile capacities be confirmed by static load testing. The Code provides the number of static load tests required, test procedures, and acceptance criteria. In the last few decades, methods other than static load testing have been developed including dynamic and rapid (pseudo-static) load tests. Recently, those methods have also been employed on several projects in New York City. The traditional approach to pile load testing in New York City is discussed herein including engineering involved in the analyses of test data with examples. In addition, several projects which included non-static load testing are discussed INTRODUCTIONPile load testing complements the subsurface information and pile design by providing further data on pile-soil interaction for the selected pile type and installation method. Traditional approaches to pile load testing in New York City involve static load tests to verify the design capacity of the piles for a given minimum factor of safety.In the late 1950's, Dr. Phillip C. Rutledge summarized his views on the philosophy of pile foundations in an unpublished, in-house document. He viewed pile foundations as good illustrations of pertinent and impertinent aspects of geotechnical engineering. In the analyses of piles he divided engineering into four general types:(a) Theoretical engineering in which decisions are made based on theoretical analyses. This represents ideal engineering, in which all factors affecting the pile design are well established or, at least, few simplifying assumptions with known effects on the analyses are made."

Jan 1, 2005

By Thang V. Nguyen, Lisheng Shao, Gary E. Taylor

"The Community Memorial Hospital of Ventura, California, proposed to build a new state-of-the-art Cancer Treatment Center with radiation shielding walls and roof. The loose silty soils at the site had the potential to liquefy during an earthquake, which would result in significant settlement under the heavy footing loads. Treatment options included various deep foundation alternatives, as well as several ground improvement methods. The choice of wet soil mixing minimized the disturbance to the adjacent hospital during construction and potential settlement. Wet soil mixing allowed the structure to be supported on a raft foundation, meeting the stringent building total and differential settlement criteria. The authors also performed unit cell 3-D finite element analyses to evaluate the behavior of the wet soil mixing system in seismic loading conditions. This paper highlights the ground improvement design, construction, QA/QC, and the research related to evaluating the effectiveness of soil mixing for liquefaction mitigation.INTRODUCTIONThe Ventura Community Memorial Hospital proposed the construction of a new Cancer Treatment Center to replace the existing structure, which was built in 1901. The hospital complex is located in a wellestablished residential neighborhood. The soil conditions at the site of the proposed structure required ground modification to support the very heavy radiation treatment section of the building and limit settlement. Originally, 90-foot-long precast piles were considered for foundation support. Based on supplemental Cone Penetration Tests (CPTs) performed, the deepest CPT did not encounter competent pile bearing strata at a depth exceeding 30.5 m (100 ft). This could result in failure of the piles under long-term conditions, especially if hydro-consolidation occurs. The more realistic pile penetration depth would have been 36.6 to 45.7 m (120 to 150 ft). In addition, the excessive noise in association with pile driving would have been unacceptable to the community, patients, and staff of the hospital, so an alternative ground improvement solution was required.The specialty geotechnical contractor recommended wet soil mixing, an economical solution of creating a soil-cement product known as soilcrete that would significantly reduce the construction related noise and provide a more complete deep foundation for the structure.SOIL CONDITIONS AND SETTLEMENT CONCERNSThe subsurface soils were interbedded (Fig. 1) consisting of loose to medium dense silty sands, and soft to medium stiff silty clays to a depth of 30.5 m (100 ft). Groundwater was encountered at depths of 9.1 m (30 ft) and historical high groundwater was at 8.5 m (28 ft) below the ground surface."

Jan 1, 2015

By Paola Campana, Maurizio Lenzi

"In the paper a non linear model for the analysis of the pile response to the axial loads is presented. The study aims to find a general analytical solution concerning the pile-soil interaction modeled by means of the method of the load transfer curves. It makes use of a criterion based on the plastic and on the hardening work locally done by the shear stresses and due to the current elastic shortening of the shaft. Then a specific solution, denoted fractal model, is found applying recurrent relations that link the shaft shear stresses and the tip normal stresses to the pile settlements. These relations are based on that one proposed by Kondner in modeling the soil samples response in the triaxial tests and then used by Chin in the inverse slope method in estimating the pile capacity by the load test results. The comparison between the model predictions and the load tests measures validate the fractal model.INTRODUCTIONThe behavior of the axially loaded piles is known to be characterized by a highly non linear trend caused by the onset of plastic and irreversible deformations in the soil starting just from the first load levels. With the purpose to reach a deeper understanding of the pile-soil interaction, the influence of the soil inelastic properties on the distribution of the axial loads and of the vertical displacements is investigated. The research starts analyzing the behavior of an infinitesimal length of a pile embedded in a non linear homogeneous soil. That initial study leads to a criterion based on the plastic and on the hardening work locally done by the shear stresses and that allows to find the axial loads as a function of the elastic shortenings of the shaft. The relation that links the pile axial load to the elastic strain of the pile material is then used. That allows to find the vertical displacements and the axial loads as function of the depth in a parametric form in which the tip settlement acts as an independent parameter. The method of the load transfer curves is used and the effects of the pile technology are included in the soil constitutive relations. The analysis is then extended to the non-homogenous soils in a very effective way. The solution is applied taking as constitutive relations of the pile-soil interface the one proposed by Kondner to analyze the soil triaxial tests and by Chin to interpolate the pile response measured in the load tests."

Jan 1, 2017

By F. W. Liang

The geology of pearl River estuary belongs in strong weathered rock quaternary geological systen, so the conditions are complication. Since 80's we built the first deepwater wharf of Shenzhen chiwan port which has 3 berths of 10000 dwt, We have built 3 berths for vessels of 40000 dwt both in Shekou Port and Chiwan port. The berths for carriers of 10000 dwt in Yantian Port of Dapeng Bay are constructing now. In the five years, We built more than 20 deepwater berths of 5000 dwt to 40000 dwt. This paper will introduce how to solve the difficulties of the complex geological conditions and how to use the new fashion construction. We will reduce the period of engineering construction and get good quality and make a good beginning of rapid development of port construction in ShenZhen Special Economic Zone.

Jan 1, 1991

By Gisele R. Passalacqua, Aly Mohammad, Joanna Smith

The $13 billion John F. Kennedy (JFK) airport construction redevelopment program includes new terminals and buildings that are supported on piles to meet the airport expansion demand due to increased travel. This paper presents a case history for JFK airport with main focus on construction activities and lessons learned. Challenges include limited head room, presence of underground utilities, and hard driving. Video inspection of pile proved very beneficial. In general, soil conditions at JFK Airport consists of sandy fill followed by a 5-foot thick organic soft layer. Below the organic layer, glacial sands occasionally mixed with gravel were encountered for great depth with increases in density with depth. The tapertube pile is an ideal choice for foundations with high capacity achieved through skin friction along the taper section. The piles are easy to splice to accommodate low head room. Pile Driving Analyzers (PDA), and Static Compression Load Tests were performed. The results of these tests are presented in this paper to illustrate the high pile capacity achieved. More detailed discussion and analysis of the test results will be presented in another paper related to the same project. Lessons learned from this project are shared to help the engineering community with future design and construction of similar projects.

By Timothy C. Siegel, Derrick Dasenbrock, Rich Lamb, Paul J. Axtell

"The axial resistance provided by deep foundations may be divided into two components: side resistance and tip resistance. The direction that the side resistance acts depends on the relative movement between the deep foundation and the adjacent soil. That is, when the foundation moves downward relative to the soil, then the side resistance is positive and acts upward. Conversely, when the soil moves downward relative to the foundation the side resistance is negative and acts downward. Research supports that both positive side resistance and negative skin friction develop in essentially all deep foundations. The side resistance distribution is a function of the soil strength and stiffness, the applied top loads, and whether the top load is sustained, transient, or a combination of sustained and transient loads. Consideration of drag load and downdrag has become more convoluted with implementation of geotechnical aspects into the AASHTO LRFD Bridge Design Specifications and its use of load and resistance factors. This paper examines the current AASHTO Specifications and presents an alternative design approach for drag load and downdrag using the LRFD framework. The alternative design approach is illustrated by two examples involving drag load and downdrag.IntroductionThe axial resistance provided by deep foundations may be divided into two components: side resistance and tip resistance. The direction that the side resistance acts depends on the relative movement between the deep foundation and the adjacent soil. That is, when the foundation moves downward relative to the soil, then the side resistance is positive and acts upward. Conversely, when the soil moves downward relative to the foundation the side resistance is negative and acts downward. Research supports that both positive side resistance and negative skin friction develop in essentially all deep foundations. The side resistance distribution is a function of the soil strength and stiffness, the applied top load, and whether the top load is sustained, transient, or a combination of sustained and transient.Consideration of drag load and downdrag has become more convoluted with implementation of geotechnical aspects into the LRFD Bridge Design Specifications and its use of load and resistance factors. This paper examines current LRFD design specifications and presents an alternative design approach for drag load and alternative design approach is applied to several examples where drag load and/or downdrag may control design."

Jan 1, 2015

By Martin D. Larisch

The construction of diaphragm walls and most large-diameter bored piles (piers) is often carried out under drilling support fluids to temporarily stabilise the excavation prior to concrete placement. In most cases such fluids are either mineral-based slurries (bentonite) or polymer support fluids. The working mechanisms of these two fluid types are fundamentally different. Designers need to consider possible fluid-related impacts on the permanent design performance of the project-specific deep foundations as well as for the temporary excavation stage during construction. Robust design methods for bentonite slurry-supported excavations have been developed in the last few decades and the working principles and associated risks of such mineral-based slurries are understood reasonably well. However, such meth-ods have not been developed in detail for polymer-based drilling fluids. This document provides a brief overview of the main characteristics of bentonite- and polymer-based drilling fluids as a guide for construction practitioners and design engineers alike. The paper also high-lights some common construction risks related to casing installation and the selection of suitable fluid systems for different ground conditions. Typical defects caused by the incorrect application of drilling support fluids, and their pro-active mitigation, are discussed, too. In addition, the basic concepts of sta-bility calculations for bentonite fluid-supported deep excavations are briefly introduced and their ap-plicability for other fluid types such as polymer-based support fluids or water are reviewed.

Nov 1, 2022

By Karl A. Higgins

In 1976, Prof. G. G. Meyerhof published a famous article in the Journal of Geotechnical Engineering titled ?Bearing Capacity and Settlement of Pile Foundations?. This article presents the authors opinions on calculating pile capacities in clays and sands, group capacities and pile settlement. A portion of the article presents correlations of shaft friction and end bearing to the Standard Penetration Test (SPT) N-value. Subsurface exploration via the Standard Penetration Test is the most widely used exploration tool in the United States, so correlations of pile capacity to N-value are significant to the practice of geotechnical engineering. Meyerhof?s SPT-N correlations are relatively simple calculations compared to other pile capacity computation methods presented in the article or found in other text books (such as the a-method, b-method, Nordlund, Vesic, Meyerhof?s semi-empirical, others) and therefore are popular amongst practicing geotechnical engineers. At the time these correlations were published by Prof. Meyerhof, utilization of dynamic testing with the Pile Driving Analyzer (PDA) was not widespread in geotechnical engineering practice. Prof. Meyerhof?s correlations appear to be based upon conventional static pile load testing of instrumented piles. Dynamic pile measurements to estimate a pile?s static capacity provides certain advantages over conventional static load testing, namely the determination of unit shaft friction values at discrete intervals along the pile, and the unit end bearing support value. The author has compiled a database of driven, displacement piles tested with dynamic methods (ref. ASTM D4945, Test Method for High-Strain Dynamic Testing of Piles). The data was collected between 2002-2010 and is comprised of displacement piles driven into coastal plain sediments in the mid-Atlantic states of Virginia, Maryland and the District of Columbia. In layered soils, dynamic testing in particularly helpful as it reveals the differences in unit shaft friction for varying soil types. One hundred ninety (190) piles are included in the database, with a corresponding 1,373 discrete shaft friction and 190 end (toe) bearing measurements. The pile type typically consisted of 12 and 14 inch square, prestressed, precast concrete piles; however, a significant number of piles were steel HP 12 or 14 inch sections. The database was sorted based upon soil type, and then correlations of shaft friction and end bearing were derived in the same or similar manner as Meyerhof?s original 1976 publication. The new correlations are compared to Meyerhof?s original values.

Jan 1, 2011

By Giovanni A. Bonita, Asher H. Peltz, Sean D. Johnson

This paper examines a complex earthwork project in the Washington DC metro area that had project delivery directly impacted by questionable instrumentation monitoring data. The case study summarizes the impacts to the project caused by questionable instrumentation data and reveals how the authors were able to utilize data to extract meaningful insights. The case study also demonstrates how clear data presentation became a key factor in maintaining stakeholder trust and facilitated progress of the project schedule. The case study highlights key points to collecting high quality instrumentation data, approaches to assess and improve value of the data collected, and techniques to reduce and interpret questionable data.

By Charles M. Wilk

"Solidification/stabilization (S/S) treatment is used to treat hazardous wastes for disposal and in the remediation/site restoration of contaminated land . SIS is also an increasingly popular technology for Brownfield (industrial property) redevelopment, since treated wastes can often be left on-site and to improve the soil for subsequent construction. This paper discusses the applicability of the technology to various wastes, basic cement chemistry relating to SIS, tests used to design treatability studies and to verify treatment, basics on implementation of the technology in the field , and examples of SIS use at brownfield sites, including a former wood preserving site, former manufactured gas plant sites, a former electric generating station, and a shopping mall development.INTRODUCTIONSolidification/Stabilization (S/S) is a widely used treatment for the management/disposal of a broad range of contaminated media and wastes; particularly those contaminated with substances classified as hazardous in the United States. The treatment involves mixing a binding reagent into the contaminated media or waste. The treatment protects human health and the environment by immobilizing contaminants within the treated material. Immobilization within the treated material prevents migration of the contaminants to human, animal and plant receptors. SIS treatment has been used to treat radioactive wastes since the 1950s and hazardous waste since the 1970's (Conner 1990). SIS continues as a cornerstone treatment technology for the management of radioactive waste, hazardous waste, and site remediation and Brownfield redevelopment."

Jan 1, 2005

By Robert L. Goehring, Fred Munene

This case history for three major additions to a tire manufacturing plant in north Georgia discusses the impact of highly variable Karst (sinkhole) geology on both foundation design and construction. For Phase 3, alternatives were considered for a heavily loaded mixing tower with up to 2,000 kip column loads. A non-traditional approach of using auger cast piles was adopted. To satisfy a risk-averse Owner, a pile load testing program including strain gauges was conducted. One test pile was cored full depth to demonstrate effective bearing on steeply inclined rock. For Phase 4, similar methodology was used at another critical mixing tower structure associated with that phase and the installation procedure was refined to reduce grout take. In Phase 5 construction, another mixing tower and the equipment pits were supported on auger cast piles. After pile installation, a sinkhole opened up between two equipment pits. Remedial grouting was performed. Development also required construction of a R&D building over a 96 inch diameter RCP storm sewer. Auger cast piles were used to support the building to avoid overstressing the existing pipe and risk separating joints. This case history outlines lessons learned while constructing auger cast piles in Karst and proving quality was built into the foundations.

By Andrzej Tejchman

Calculation of pile foundations should possibly truly reflect its real work, mainly with respect to the value and distribution of settlements, pile internal forces and bending moments within a slab. Many empirical and theoretical methods serving for an assessment of the settlements of pile group overestimate its actual values obtained from field measurements (see Tejchman et al., 2001). In the paper a simple engineering method for calculation of pile foundations is presented. The method takes into account the interaction between the slab and a soil together with the phenomenon of non-uniform deformation of the soil-pile subsoil, particularly under large foundations. In the method the scheme of the slab resting on one-parameter elastic subsoil is assumed. The comparison of the calculation results for existing pile foundation with the field measurements shows good agreement between those values.

Jan 1, 2002

By Ali S. Fayad

"In June 2014, Orange County Flood Control District (OCFCD) completed construction improvements of the East Garden Grove-Wintersburg Channel for a price of $42 million. Instead of the pre-existing traditional trapezoidal levee, the channel was improved with a vertical compact levee. Dubbed Soil-Mix-Sandwich (SMS), this geo-structural and environmental solution for coastal channel improvements, underlain by liquefiable soil strata, was both a design and construction innovation. It employed Deep Soil Cement Mixing (DSCM) within the confines of a hydraulically-pressed (Giken Method) sheet pile duo. SMS was unique because it incorporated both subterranean and supra-dredge-line soil mixing within a very narrow workspace. Its DSCM pattern aimed at optimum densification of the workspace and was confirmed during the construction process. It availed the DSCM sub-contractor (Hayward Baker Inc.) the opportunity to demonstrate the fitness of their huge wet-mixing machinery within a very confined access-area and introduced approximately 70,000 cubic yards of DSCM within a limited 15 foot workspace width that stretched for a mile. The sheet pile duo created a construction-enclosure that became a stay-in-place load resisting system. PROJECT CHRONOLOGY AND LOCATIONAn Orange County Flood Control District (OCFCD) project-report was commissioned to study the East Garden Grove Wintersburg channel (OCFCD facility # C05). The report examined the hydraulic conveyance of the C05 channel and was concluded in 1994 by Williamson & Schmidt. The project-report did not encompass extensive geologic studies; but it provided several alternatives for channel improvement. It recommended a single row of sheet piles as the preferred alternative for the downstream reach.The most downstream reach of the C05 channel is located in an environmentally sensitive area, in City of Huntington Beach, California, USA. Its site includes seismic chasms that surface within the C05-footprint (the Newport- Inglewood tectonic fault). Extensive deposits of liquefiable soil exist beneath the channel. Furthermore, tidal-influence prevails against the channel levee. Implementation of a successful design for channel improvement emerged after several traditional concepts were deemed unacceptable by geotechnical consultants. OC Public Works (on behalf of OCFCD) was in need of a design and construction technique that mitigated many associated risks. From these circumstances, Soil-Mix-Sandwich was born and was referred to in the rest of this discussion as SMS. OC Public Works required the SMS design concept to undergo verification by independent geotechnical consultants. SMS chronology from conception to construction can be summarized as follows:"

Jan 1, 2015