Geotechnical Engineering Portfolio

The Barbours Cut Terminal (BCT) is located along the Barbours Cut Ship Channel, between the city of La Porte and Morgan’s Point, on the northwest shore of Galveston Bay, Texas. This container terminal is owned and operated by Port of Houston Authority (PHA). BCT is a 6,000-foot long continuous marginal wharf that was originally designed in 1979 and 1982, with a major upgrade in 2012. The PHA has been upgrading this marginal wharf over phases to accommodate larger gantry cranes of 100-ft gage. Initial terminal upgrades for a similar purpose were implemented by others in Wharves 1, 2 and part of 3 (easternmost wharves) of BCT. This project involved the upgrades on the remaining 700-foot length of Wharf 3 and a 350-ft length of Wharf 4. Two new rows of deep foundations (front row and back row) were designed to support the new 100-foot gage ship-to-shore (STS) gantry cranes as part of the continuing upgrades at BCT. LCRA directed and interpreted new geotechnical field investigations and associated laboratory tests of soil samples, modeled the new foundation system, provided nonlinear springs to represent soil-structure interaction models of the complete system (performed by WJE), and performed several checks of global and local models of slope stability in the site.

Lymon C. Reese and Associates, Inc. (LCR&A) was retained by Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, as a support team for a research project on Laboratory Testing of Lateral Load Response for Monopiles in Sand. The current design methods for laterally-loaded offshore foundations in sand, API RP 2GEO (2011) and DNV (2013), are unverified for the large diameter, relatively short monopiles used for offshore wind turbines. The following factors are either questionable or not addressed by current design guidance for wind turbine monopiles: (1) monopiles have a significantly large pile diameter and small length-to-diameter ratios; (2) monopiles are subjected to large numbers of relatively small-amplitude cyclic loads that affect the lateral stiffness and the accumulated lateral displacement/rotation. The objective of this research is to evaluate the suitability of existing guidance for the design of laterally-loaded monopiles at small displacements and to provide recommendations for improving design methods for monopile foundations in sand. This project was sponsored by United States Department of the Interior, Bureau of Safety and Environmental Enforcement, Washington, DC.

Lymon C. Reese and Associates, Inc. (LCR&A) was retained by Aubrey Silvey Enterprises, Inc. as the consulting expert for providing analyses and professional opinions on the root cause of cracks found in some of foundation soils at Mountain Air Wind Farm, Idaho. The measurement and observation of the performance of the foundation system at Mountain Air Wind Farm, conducted in August 2015, suggest that soil crack around foundations are noticeable among some of wind turbines built in 2012. LCR&A provided engineering review and assessment of the performance of existing foundations, identifying possible causes for the observed soil crack on some foundations, and the engineering recommendations for the client.

The Port of Houston will deepen the existing ship channel to accommodate large vessels. The new channel depths and the accompanying deepening of the existing berths at the Manchester 2 & 3 wharves may undermine the pile foundations. The Port of Houston engaged Wiss, Janney, Elstner Associates, Inc. (WJE) and LCRA as its team member to investigate the effects of their plans for deeper dredging. The Manchester 2 Wharf was originally constructed on a field of closely spaced driven wooden piles around 1921. The original superstructure was replaced with a reinforced concrete wall and slab structure built in 1948. The majority of the original piles were reused under the new superstructure but with some limited replacements. For the geotechnical engineering review, LCRA investigated subsurface conditions based on available geotechnical investigation reports in the past 40 years, studies the represented soil parameters of subsurface layers, computed the geotechnical pile capacity under axial loads and lateral loads, and analyzed the stability of slope under the existing and new channel depth based on short-term, long-term, and rapid drawdown conditions during the storm surge.

XR Structural is working on inspection for an overpass bridge (Bridge 47) near Boggy Creek Road at Texas State Toll Road SH 130, at Lockhart Texas. The slope of the highway embedment in this area of SH 130 has experienced soil movement and slope failure in backfilled and shallow layers. Repairs of sections of embedment slopes at each side of the overpass bridge have been conducted in recent months. Lymon C. Reese and Associates (LCR&A) was invited to join the inspection team led by XR Structural for investigation of any potential of slope failure or soil movement which may cause damage on the overpass bridge.

Lymon C. Reese and Associates, Inc. (LCR&A) was retained by CWE Consultants, ULC in Canada for providing analysis/design calculations of the pile foundation for Jericho Wind Turbine T-7 based on the geotechnical investigation report and the load information. The wind turbine site is within the rural community located in the Municipality of Lambton Shores and the Township of Warwick, in Lambton County, Ontario. The project will involve the construction of 1.5 MW wind turbines at selected locations. The soil conditions vary across the large project area. Conditions appear to be favorable towards the use of shallow spread footings except for Turbine T7, where compressible sublayers can generate excessive settlement for the shallow gravity foundation. Deep foundations using end bearing low-displacement steel H-piles driven into bedrock and/or very dense soils immediately above bedrock are recommended to be the most effective foundation option for Turbine T7. LCR&A provided the geotechnical pile capacity under tension and compression loads of proposed H-piles. Soil resistance curves including p-y curves and t-z curves were derived for soil-structure-interaction analyses. Wave equation analyses were also performed for the pile drivability study.

Lymon C. Reese and Associates, Inc. (LCR&A) was retained by Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, as a support team for a research project on design of wind turbine monopoles for lateral loads in clay soils. The objective of this research was to evaluate the suitability of API RP 2A/2GEO for the design of wind turbine monopiles and to provide recommendations for improving the design method for these types of foundations. This project was sponsored by United States Department of the Interior, Bureau of Safety and Environmental Enforcement, Washington, DC.

An older P&H Foundation system suffered damages due to loads arising from extreme occurrences of scour. LCR&A engineers evaluated and designed a strengthening system consisting of new drilled shafts and pile cap built around the existing foundation structure. The system is believed to provide safe response for the design life of the structure and at competitive costs when compared to the limited alternatives.Services Provided:1. Conducted soil-structure-interaction analysis for foundation behavior and dynamic stiffness;2. Designed drilled shafts and pile cap along with detailing;3. Provided final drawings for certification and construction permit;4. Evaluated shop drawings and other engineering requests for construction; and5. Provided field inspection and QA during construction.

The Mountain View IV wind farm has a total of 49 Mitsubishi Heavy Industries (MHI) Model 1000A 1.0 MW generators with 60-m hub heights. The turbine towers were constructed on cylindrical steel monopoles supported by a unique foundation system with closely-spaced drilled shaft and tight pile cap.The wind farm is located in Palm Springs, California, in an area that is subject to high seismic loading from the nearby San Andreas Fault Zone and severe scour (10 to 12 ft) due to the project location in a floodplain. The new drilled shaft foundation (under patent application) has unique features and special design to meet the performance requirement from the turbine manufacturer and the environmental challenges. The project involved a thorough design with specialized software products, including analysis of seismic loading, dynamic stiffness, soil-structure interaction, concrete and steel fatigue and drilled shaft capacity. An evaluation of the actual response of this innovative foundation system is currently ongoing using specialized instrumentation that were placed in selected drilled shafts and pile caps.Services Provided:1. Conducted soil-structure-interaction analysis for foundation behavior and dynamic stiffness;2. Designed drilled shafts and pile cap along with detailing;3. Designed and installed instrumentation system for structural monitoring during operation;4. Provided final drawings for certification and construction permit;5. Evaluated of shop drawings and other engineering requests during construction; and6. Provided field inspection and QA during construction.

Lymon C. Reese and Associates, Inc. (LCR&A) in Austin, Texas was retained by China Oilfield Services Limited (COSL) to review geotechnical investigation reports and provide assessments of soil-response curves (t-z, Q-z and p-y curves) and group effects of pile foundations for the proposed new offshore platform LF7-2 in the South China Sea. The water depth at the proposed platform location is approximately 107 meters. The soil report indicates interbedded layers of silty fine sand and clays ranging from firm to hard consistency.The scope of services from LCR&A includes discussion and recommendations on soil-response curves (t-z, Q-z and p-y curves) developed by COSL, assessment of axial displacement and lateral deflection of pile groups, generating z-modifiers (for t-z data) and y-modifiers (for p-y data) to be served as part of recommendations on the sub-structure input data for structural analyses of the platform. The engineering services from LCR&A also include the discussion of a potential punch-through failure in the sandstone layer and of general practices for selections of pile penetrations and wall thicknesses in the various pile sections.

Technical review of geotechnical engineering reports and validation of recommendations of soil parameters and soil response curves (t-z, Q-z and p-y curves) to be used in the design of pile foundations for a new offshore platform in the South China Sea. The water depth at the proposed platform location is approximately 132 meters. Project site predominately consists of cohesive fine-grained soils with several interbedded layers of coarse to fine sand and silt.

The objective of this research project is to provide TxDOT with guidance for the design of drilled shaft retaining walls in expansive clay soils. The research involves instrumenting a full-scale drilled shaft retaining wall constructed in an expansive clay soil and monitoring its performance over three years. The wall consists of 25 drilled shafts with a diameter of 24 inches and spaced 30 inches on center. The wall supports a 15-foot deep excavation. Three shafts were instrumented with internal inclinometers and optical strain gauges. The total length of shaft is 835 lineal feet, with 735 lineal feet of drilling. Engineers from LCR&A are on the advising board with analytical help for the different models of the system and interpretation of measurements.Separately, LCR&A also provided guidance and support for the instrumentation and monitoring system

LCR&A was retained to develop and apply 3-D numerical models to evaluate the effect of settlement and flood loading on T-wall batter piles for use on the Hurricane Storm Damage Risk Reduction System in New Orleans, Louisiana.Three-dimensional, finite-element models representing two different configurations were developed to evaluate pile bending due to settlement. The piles were represented as solid elements and connected to the soil through interface elements (contact elements) that allow both slip and separation. The model was developed to capture the behavior of the settlement from soil surcharge loading and flood side loading from the hurricane storm surge. The mesh is of sufficient size and refinement to permit accurate calculation of stresses and deformations at the locations of interest. About 900,000 elements and 200,000 nodes were employed to discretize the T-wall system and surrounding soil. Nonlinear constitutive models were used to represent the soil: the Mohr-Coulomb model and the Bounding Surface Plasticity model, which is based on the concepts of critical state soil mechanics. The general-purpose finite element analysis program, ABAQUS, was employed to run all finite element analyses.

A detailed review was made on the response of patented P&H piers used as foundation system in the Vestas V-80 1.8 MW wind turbines at Buffalo Gap Wind Farm. The review originated due to observation of small gaps between soil and foundation that may have resulted from resonance effects caused by the fundamental natural frequency of the structural system of each tower being very close to the one-per-revolution (1P) frequency of the turbine. Field monitoring data was reviewed along with construction details of the foundation and soil studies at the site. A report was provided regarding the nature of the problem and its possible long-term effects on the foundation systems.

Lymon C. Reese and Associates, Inc. (LCR&A) was asked by SunPower Corporation to evaluate driven-pile foundation system for supporting T0 ground–mounted solar tracking system in Florida based on the full-scale loading tests. The galvanized pipe piles with 4.5-inch OD and 10 to 15 ft of penetration were installed at two different sites for tension-loading tests and lateral-loading tests.Services provided:1. Review soils and driven-piles testing reports.2. Perform engineering calculations and reconcile with testing data.3. Recommendations on installation methods and other proven techniques to improve the tension capacity of proposed driven piles.

Lymon C. Reese and Associates, Inc. (LCR&A) was asked by Sigma Energy Solutions in New York to review the foundation design for V90 wind turbines, which consists of an octagonal concrete base with a cylindrical central pedestal. The central pedestal has an outer diameter of 4.8 m and a height of 1.1 m. The width of the octagonal concrete base is 17 m. The proposed development for the site consists of nine (9) wind turbines and one substation.Services Provided: 1. Critical review of geotechnical report to extract data needed for the analyses to be performed.2. Selection of parameters describing the properties of the soil needed in the computations. A significant number of parameters describing the soil are needed, including the properties related to the shear strength of the soil, the unit weight, information related to settlement and the expected position of the water table during the life of the structure.3. Computation of the bearing capacity of the foundation under both service and maximum loads.4. Computation of the lateral resistance against the foundation using both service and maximum loads.5. Computation of the rotation of the structure due to the wind load. The short-term stiffness of the soil must be estimated on the basis of the available data. Gapping between the foundations and the soils should not be developed during operation. Any potential deterioration in the contact surface due to gapping was investigated. 6. Computation of the settlement of the foundation under long-term loading. The settlement might be caused by the ejection of water from the soil due to vertical loading and to the possible re-orientation of the grains of soil.

The P&H pier foundation typically consists of a large diameter, cast-in-place reinforced-concrete pier with an outside diameter of 13 to 18 ft and the inside diameter of 10 to 14 ft. The length-to-diameter ratio typically is 2 to 4. Therefore the behavior of this type of foundations is not similar to those of the traditional deep foundations. One unique characteristic of this type of foundation is that the rotation of the foundation may generate significant resistance from the soil against the overturning moment. This rotation may lead to the soil cracking at the interface between soil backfill and the undisturbed soil at the edge of the original foundation excavation. Sigma Energy Solution (SES) retained Lymon C. Reese and Associates, Inc. (LCR&A) in Austin, Texas to review the measured field data and the original design of foundations for evaluation of the serviceability of the foundations.Services Provided:1. Critical Review of Selected Soil Parameters.2. Evaluation of Deflection and Rotation under Extreme Loads and Service Loads for V-90 Foundations. 3. Investigation of Stress-Distribution by Using 3-D Finite-Element Model.4. Stability Study Under Extreme Loads.

Sigma Energy Solution (SES) retained Lymon C. Reese and Associates, Inc. (LCR&A) in Austin, Texas to review the design documents and the geotechnical investigation report for P&H Pier Foundations at Snyder Wind Farm, Texas. The focus of this review is on professional opinions regarding the validation of modification factors applied by the designer on P&H piers, which in general have an outside diameter ranging from 14 ft to 18 ft.Services Provided:1. Critical Review of Representative Soil Strength Parameters based on the Geotechnical Investigation Report.2. Comments on Scaling Factors in LPILE (Beam-Column Model) Analysis.3. Model Including Tip Resistance and Side Friction for Large Piers.4. Stability Study Under Extreme Loads.

Earth Systems Southwest (ESSW) retained Lymon C. Reese and Associates, Inc. (LCR&A) in Austin, Texas to provide professional opinions regarding the safety factor and its relationship with the appropriate design strength selected for the soil. The focus of this review is on the validation of modification factors applied by the designer on P&H piers.Services Provided:1. Critical Review of Representative Soil Strength Parameters based on the UU Triaxial Tests.2. Comments on Reasonable Factor of Safety under Extreme Loads.3. Size Effects on Soil Lateral Resistance (p-y curves).4. Comments on Remediation Plan on Foundation.

Lymon C. Reese and Associates, Inc. (LCR&A) was retained by Eurus as the third-party reviewer in resolving outstanding issues between the foundation designer, Earth System Southwest (ESSW), Patrick & Henderson (P&H), and the bank’s engineer – Garrad Hassan (GHA) with respect to the engineering design for the wind turbine foundations at Crescent Ridge Wind Farm, Tiskalwa, Illinois. The focus of this review is regarding to the methodology applied by the designer on P&H piers.Services Provided:1. The Acceptable Factor of Safety for Overturning Stability.2. The Method Selected for Estimation of Rotational Stiffness.3. The Effectiveness of the Bottom 2 feet of the Plain Concrete Section to Resist Moment.

Study of the response and preliminary designs for suction piles were prepared for a client with platforms in the Gulf of Mexico under approximately 6,000 ft (1,800 m) of water. Evaluations were made of the following: axial and lateral holding capacities, installation analyses, determination of soil reactions for structural design, and buckling analyses. Three analytical tools were employed in analyzing the suction pile for its holding capacity under combined ultimate axial and lateral loading: method of plastic limit analysis, method of nonlinear load-transfer functions (p-y, t-z and q-w curves), and method of finite elements. Suction piles with around 100-ft (30.5 m) penetrations and 18-ft (5.5 m) diameter were evaluated under different chain loads and angles. Chain geometry in the soil was evaluated under different loads and angles from ground surface.

LCR&A conducted advanced modeling by using the finite-element method for prediction of the stress contours and settlement of the foundation of a bauxite transformation plant. LCR&A proceeded to study the stress distribution and short-term elastic settlement of foundations with a three-dimensional finite element model. The long term settlement was estimated based on Terzaghi’s theory for one dimensional consolidation. The numerical model was large and complex, over 1.2 million elements were used to model the 28 piled-raft foundations, supported by 2,502 CFA piles, and the surrounding soil. A full three dimensional model was prepared for analysis because of the unsymmetrical nature in the layout of the 28 raft foundations.

Engineers from LCR&A were contracted to perform a detailed geotechnical review of the proposed foundation system for a multi-story building in Port of Spain, Trinidad. The report contained a design table with pile diameters and penetrations according to various axial and lateral load combinations. Recommendations were made on additional soil investigations, use of bentonite slurry and the performance of pile tests.

Several localized failures occurred over the course of a few months in 2003 on a large retaining wall in Colonia Florencia, Tegucigalpa, Honduras. The owners contracted Lymon C. Reese & Associates (LCR&A) to provide engineering counseling regarding the observed failures and the proposed solutions. The retaining system consisted of mechanically stabilized earth walls having a maximum height of approximately 13 meters (45.7 ft) with a total length exceeding 150 meters. LCR&A reviewed the initial design records along with recorded construction procedures and fill materials, conducted studies of slope stability, organized and reviewed new soil studies at various locations, and reviewed proposed repairs and solutions.

Engineers from LCR&A performed a preliminary site visit and evaluations of the design and construction recommendations prepared for the development at Esso Estacion Milla 1 in Panama. Several observations were made regarding the topography at the site, variations of soil layers, design method and construction process.Study of Soil Response and Improvements Using Sand Piles and Study of Alternative Methods for Soil Improvements for Container Terminal Project in Colón, PanamáProject Location: Colón, Republic of PanamáClient: Dillon Construction, Inc. (DCI)Dates: February 2003 to August 2003Dillon Construction, Inc. (DCI) was the general contractor for Phase II of the Colon Container Terminal project in Colón, Panamá. The project required a large number of sand piles to be installed in areas under the quay and in the container yard. Project specifications also established guidelines on construction procedures and requirements for measurements of performance on the improved soils.DCI engaged the services of LCR&A for the prediction of the type of soil response and improvements that can be expected at the site. LCR&A was also consulted for recommendations of alternative construction methods for the sand piles that may provide equal level of improvement, faster construction and/or better economics.Response of Driven Piles with Various Pile Hammers for Container Terminal Project in Colón, PanamáProject Location: Colon, Republic of PanamaClient: Dillon Construction, Inc. (DCI)Dates: August 2003 to November 2003The driving and refusal criteria of steel pipe piles of 700 and 600 mm in diameter and various wall thickness were analyzed by LCR&A for DCI's Phase II of the Colon Container Terminal project in Colón, Panamá. The piles were analyzed for a variety of available hammers and at different energy settings. The recommended criteria was found as appropriate to avoid damages of the piles while still penetrating sufficiently into the founding "Gatún" layer.

Lymon C. Reese & Associates (LCRA) was engaged by Geotech Associates, Ltd. to perform an evaluation of laterally-loaded piles in liquefied soil layers for a site in Trinidad, West Indies. Based on liquefaction analyses conducted by Geotech Associates Ltd, the liquefaction potential is high for the subsurface layers at the site. However, lateral spreading during and immediately after the earthquake may not be possible because the site in general has a flat surface. LCRA conducted two analyses for evaluation of the lateral capacity of piles at this site based on the worse and best soil conditions revealed in the soil boring profiles.

Condon-Johnson & Associates, Inc. (CJA) was the foundation contractor for the Solano County Government Center project in Fairfield, California. The project’s General Contractor was Clark Design/Build of California, Inc. (Clark). CJA engaged the services of Lymon C. Reese & Associates (LCRA) to finalize the pile design provided for bidding, to provide the appropriate background of engineering calculations and for site inspections and reporting during construction. LCRA was also consulted for recommendations of alternative pile reinforcement that provided similar or better response and project savings in construction time and/or quality control. LCRA provided engineering support during construction for the inspection and study of solutions to variations that were found or accidentally made at the site.

A derailment of the Union Pacific Railroad occurred in the early morning of Sunday, July 21, 2002. The derailment was apparently caused by an erosion failure of the railroad embankment. The erosion occurred after a recent, two-day period of high rainfall in the area. Rainfall totals were estimated to be between 1.5 to 2 inches and approximately representing 15 to 20 percent of the average annual rainfall in this part of Texas. Engineers from LCR&A were contracted to determine the causes of soil erosion and to provide recommendations for future actions. LCR&A determine that the derailment was caused by “subsurface erosion” or “piping” that undermined the railroad bed. This erosion had developed over a long period of time and resulted from presence of soil highly susceptible to this erosion, combined with a weather event that supplied large volume of water entering the exposed erosion conduits. Several actions were recommended for prevention methods of future erosion damages.

Two transmission towers for 138-kV lines help to deliver energy from the Holly Street Power Plant across Town Lake in the City of Austin. These towers were evaluated for an increased number of transmission lines thus requiring a review of their structural integrity and foundation response.These towers were built in the late 1950’s and their foundation consisted of large concrete caps on top of irregular combinations of straight and raked steel piles made of H sections. The penetration of those piles was not clear from the original plans and a site investigation with non-destructive sonic methods was performed by LCR&A. The tests were based on the use of sonic waves to investigate the length of the existing piles under the concrete caps. Dynamic loads were generated with small blows of hammer impacts on the pile cap and electronic transducers of high sensitivities recorded the signals. Pile lengths were computed based on traveling time and speed of compressive waves on each test pile.Capacities of the existing foundations were evaluated using 3D models of the cap and piles and using non-linear soil properties. Two designs were made for strengthening alternatives, one based on screw anchors and one solution based on drilled shafts.

The services from Lymon C. Reese & Associates (LCR&A) were requested for the recommendation of preliminary p-y curves for a project in Brazil. In general, the consulting project from Starmark Offshore consisted of evaluating offshore risers in the general area of Camamu Bay, State of Bahia, Brazil. The general site in Camamu Bay is formed predominantly by calcareous soils of different grain sizes and cementation. LCR&A made a historical review of deep foundations in such difficult sites and also prepared a recommendation for p-y curves to be used in preliminary analyses.

Five transmission towers for 345kV lines in Bastrop County, Texas, help to deliver energy from the Fayette Power Plant to the city of Austin. The loading conditions of these towers have been modified and the existing foundation elements had to be revised under increased loads. A geotechnical investigation project was carried out by LCR&A for locations near each tower. A report was prepared and delivered to the client.Results from the geotechnical studies were used while modeling the existing drilled shafts under new loadings. Site inspections helped to determine additional constraints or construction information for the existing structures. A full report was delivered to the client regarding the expected response of the existing foundation. The report included recommendations for strengthening four of the twenty drilled shafts under investigation.

The client contracted LCR&A to provide engineering services related for a geotechnical investigation. LCR&A was also contracted to provide an engineering report of the geotechnical investigation that included recommendations for the design of the new pavement and a small retaining wall.The geotechnical investigation followed ASTM standards for soil sampling and laboratory testing. Recommendations for pavement were based on the City of Austin’s FlexiblePavement Design System that takes into account traffic volumes, serviceability, maintenance, construction cost as well as other engineering constraints. Studies were made regarding the type of retaining wall and soil stability at the site.

The City of Austin is adding a left-turn lane from eastbound Riverside Dr. to Wickersham Lane and an acceleration lane on westbound Riverside Dr., west of the u-turn from Pleasant Valley Road. The client contracted LCR&A to provide engineering services related to the geotechnical investigation at these sites. LCR&A was also contracted to provide an engineering report of the geotechnical investigation that includes recommendations for the design of the new pavement.The geotechnical investigation followed ASTM standards for soil sampling and laboratory testing. Recommendations for pavement were based on the City of Austin’s Flexible Pavement Design System that takes into account traffic volumes, serviceability, maintenance, construction cost as well as other engineering constraints.

Structural casings are commonly used as one of the foundation components for offshore wells in the oil industry. The design of these casings must consider drilling and production loads (lifecycle loads) in static and cyclic modes. The practices for the design of these casings for offshore platforms are outlined by the American Petroleum Institute in recommendations from API RP 2A.Modern concepts of soil-structure interaction were developed by LCR&A in order to study the response of structural casings. The new method developed for Marathon Oil Company considers the lateral resistance of the soil as a nonlinear function of the deflection of the casing while analyzing the effects of various axial loads placed at different levels above the wellhead (using p-d effects). A commercial software was developed by engineers from LCR&A and results from this new program compared very well with results obtained from very complicated and costly finite-element models prepared by other consulting firms.

The manual to be written will include practical guidelines for the design and construction of drilled shaft foundations for hydraulic civil works. The manual will be written as a practical guideline for experienced civil engineers when designing drilled shaft foundations. Topics to be addressed include methods to analyze and design individual and groups of drilled shafts subjected to axial, lateral, and torsional loads due to hydraulic loadings, superstructure loadings, retained earth, and moving earth.The manual is being prepared with materials from existing design and construction guidelines developed by LCR&A for the Federal Highway Works Administration (FHWA) and the Association of Drilled Shaft Contractors (ADSC). Other information used for the manuals come from the Electrical Power Research Institute (EPRI), American Concrete Institute (ACI), and existing U.S. Army Corps of Engineers (USACE) manuals.

The City of Austin is extending the existing South first Street for a total length of about 10,000 ft south of its current termination. The roadway covers a total width of 120 ft, carrying four lanes of traffic, two bike lanes, two pedestrian sidewalks, and a median of 20-ft width. Two bridges of about 500 ft and 400 ft lengths are necessary for the crossings of the new roadway over Slaughter Creek and Nichols Branch Creek. The roadway crossings are designed with twinbridge structures over the creek, each bridge with a width of 39 ft, each carrying two lanes of traffic, a bike lane, and a pedestrian sidewalk.The clients retained the services of LCR&A to coordinate and perform the required soil investigations for the bridge and roadway projects, and to perform the analyses and design of the foundation system for the bridge structures. LCR&A was contracted to provide all detailed drawings and construction inspections related to the foundation system.

The project was for the extension of existing marine facilities of ARCO at Cherry Point, approximately 15 miles north of Bellingham, in the State of Washington. The new facility was designed for accommodating a range of sizes of ships, tankers, and barges up to 70,000 DWT. The project was developed in closed cooperation with Ben C. Gerwick from San Francisco, California.LCR&A was retained by the clients to provide complete analyses and design of the foundation system for the dock, including connecting trestle, loading platform, breasting dolphins, mooring dolphins and catwalks. The foundation for breasting and mooring dolphins consisted of 84-inch O.D. steel-pipe piles penetrating 40 feet into stiff glacial till, below 40 to 60 feet of water, total pile length of 120 to 140 feet. The design require careful attention to the installation of this large size piles into the glacial till, composed of sandy gravel with final blow counts in the order of 4-inch penetration for over 100 blows. In order to drive such piles, LCR&A was instrumental in the design of a special marine offshore-type pile driving hammer.In addition, LCR&A provided its expertise in geotechnical engineering with technical considerations and details related to the construction of the foundation for the marine structures. Construction was completed successfully in December of 2000.

LCR&A was retained by the client to study the stability of existing slopes and cause for signs of distress in the pavement at the subject site. The contract also covered the initial design of a drilled shaft suppressor system and its improvement to the factor of safety for the stability of the existing slopes. State-of-the-art computer programs were used to study the stability of existing and strengthened slopes.

Improvements on the wastewater systems of several neighborhoods were planned by the client. The incorporation of these projects require several excavation projects in city streets containing extensive array of underground utilities. LCR&A performed the soil investigation at the proposed sites and made recommendations for the type of excavations and expected soil difficulties. Locations of existing underground utilities (water, wastewater, electric, gas, telephone) were determined by LCR&A engineers in each project. Geotechnical reports were submitted and helped the client during cost estimation. The reports were later included as part of the bid documents provided to the contractors.

LCR&A engineers functioned as members of a Peer Review Team responsible for evaluating the condition and integrity of foundation piles after unexplained movements had been observed during construction. LCR&A engineers evaluated the analyses by engineers of record, the soil investigation and laboratory testing program, slope inclinometer measurements, slope stability, and pile-driving procedures used during construction. A report the clients discussed the likely causes of movement, response of piles in moving soil, and recommendations for completing the project.

A large, 480-MVA, auto-transformer was designed for an existing slab foundation at the subject site. The new transformer impose a 25% increase in axial-design loads for the existing slab foundation and requires a larger footprint. LCR&A was contracted to design the strengthening details needed for the existing foundation. Complete set of construction drawing details were provided, as well as construction specifications.

The complete design for an electrical substation in the City of Austin was performed by LCR&A. Foundation structures consisted of drilled shafts and slabs-on-grade. Innovative foundation details were engineered in the thick slab required for the heavy 50MVA transformer and oil-containment structure. Complete foundation details, computation sheets, and construction specifications were delivered to the client.

As authorized by K.C.I. BV in Holland in November 1995, Lymon C. Reese & Associates conducted a study for the behavior of a suction pile. The suction pile was to have a diameter of 9 meters with the wall thickness of 30 mm to 40 mm. One critical element in design of suction piles at different environments is to analyze the penetration needed for the suction piles to sustain wave loads created by the maximum storm.Two methods were used for this study. One method employed three-dimensional, finite-elements, which can provide detailed distribution of stress-strain in the vicinity of the pile. The other used a simplified pile-group model, which employs well-accepted, empirical soil resistance embodied p-y and t-z curves. The results from both methods seem to be consistent and both are suitable models to study the stability of suction piles. Both methods clearly indicate that a suction pile with a penetration of 9 meters is more stable for the soil conditions at this particular location.

Cracks were found on several foundations used for transmission lines in the city of Austin. Members of LCR&A were invited by the City of Austin to join the investigation team coordinated by Power Engineers for a detailed study. The tasks conducted by LCR&A were: investigation of the cause of cracks, evaluation of the stability of the structures under their existing conditions, development of a remedy plan for repairs, and recommendation on improvement for future designs and construction methods.

The differential settlement that occurs in a cap of impermeable soil over a landfill site is regulated by strict limitations from EPA requirements. LCR&A conducted a study using three-dimensional, eight-noded finite elements. A detailed investigation was made of the pattern of deformation, stress distribution, and the long-term settlement, with and without the proposed clay cap.Preliminary Design of Piles for Retaining Walls at U.S. 290 and 7th StreetProject Location: Oakland, CaliforniaClient: Brown & Root; Houston, TexasDates: 1994-95The piles that were designed to form the retaining walls consisted of GeoJet units (soil-cement piles with steel inserts). Models of existing soil layers were made with provisions for design earthquakes. The retaining walls varied in height from 8 ft to 24 ft and were designed with none, one, and two soil anchor tie rods.

The project involved the study and a preliminary design of the foundation system for crane towers in a planned large coal terminal for the port of Los Angeles, California. Partners of LCR&A produced the preliminary computations and modeled the soil with consideration for earthquakes (possible liquefactions of upper granular soil layers).

Partners of LCR&A designed footing caps and replacement drilled-shafts for the foundation of several single columns of the Fair Park Bridge Reconstruction Lanes in Dallas, Texas. Theories and models of strut-and-tie systems were used to perform the footing beam design. Results were later checked with more conventional design methods from ACI. The replacement shafts were designed by modeling the soil under lateral loads with non-linear p-y curves and under axial loads with nonlinear t-z curves. The proximity of failed shafts was taken into account with modifications to the mentioned p-y curves.

Associates of LCR&A were invited to evaluate the problems of buckling on conductor piles during installation. An analytical model was used to study the cause of buckling under various stress conditions. A recommendation for quality control during pile driving was presented to the owner for improvement.

Associates of LCR&A were retained by Woodside Offshore Petroleum Pty. Ltd. to make a study of the pile/grout/soil connection with respect to the possibility of creep of the grout and the supporting soil. A study of numerous documents was made. Recommendations were presented in a report.

Associates of LCR&A received from Rashid Geotechnical and Material Engineers, Saudi Arabia, a report entitled “Draft Engineering Report, Geotechnical Investigation 1990, Safaniya Gosp-4 Complex, Arabian Gulf,” and were authorized to prepare a report presenting additional comments on the following topics that related to the design of piles for the subject site: load transfer curves for axial loading, cyclic effects for lateral loading, drilled-and-grouped piles, and group effects.

Associates of LCR&A were requested to review the design of the pile foundations for the subject project. The soil profiles were analyzed and a number of typical categories were selected. Studies that were carried out included the behavior of piles under short-term axial loading and under sustained loading. Also, procedures were proposed for the behavior of pile groups under lateral loading. The computer program GROUP1, developed by Ensoft, Inc., was used in making the computations, and a report was prepared giving results of the study.

The U.S. Army Corps of Engineers has responsibility for numerous lock structures on the Mississippi river. The principal objective of this study was to develop a rational method for the analysis of the stability of pile-supported lock structures. The continuing study included the identification of possible failure mechanisms for the foundation, modeling the response of a pile group for a lock structure, investigation of the mechanism for piles that pass through a potential slide, and development of a model to describe the interaction between piles and soils due to relative movement.

Sargent & Lundy Engineers were designing a power plant in Shanghai, China. The subsurface consisted of very soft alluvial clay and medium dense sand. Because of a potential downdrag problem on the driven piles that were proposed, associates of LCR&A were retained to analyze the behavior of piles due to settlement of the soft clay at the site.

The pile foundations for the North Rankin “A” platform were embedded in calcareous soil, and a number of factors indicated the need for strengthening the foundations. Several experts were called in for technical advice. Use of underreams was being considered for improving the foundation. On this project, associates of LCR&A were retained to study the behavior of the groups of under reamed piles under both axial and lateral loadings.