Structural Engineering Portfolio

Strengthening of Drilled Shaft at Railroad Crossing near Rayford Road, Montgomery County, Texas

Montgomery County, Houston, Texas
WW Foundation Drilling, Ltd.
2017
Lymon C. Reese and Associates, Inc. (LCRA) was retained by WW Foundation Drilling, Ltd. to strengthen one of 42 inches OD drilled shafts for railroad crossing near Rayford Road in Montgomery County, Texas. The drilled shaft which experienced a steel reinforcing issue was installed at a bridge bent. LCR&A reviewed the existing plan and design capacity of drilled shafts. It is important of not altering the position of the shafts in the bridge bent. LCR&A provided an acceptable structural design for strengthening the drilled shaft instead of replacing the as-built shaft.

Geotechnical and Structural Review and Retrofit of Wharf City Dock 9, Port of Houston

Port of Houston, Texas
Wiss, Janney, Elstner Associates, Inc. & Port of Houston Authority
2016
Wharf City Dock 9 (CD 9) is located on the western edge of the Turning Basin Terminal at the Port of Houston. During a condition assessment performed by Wiss, Janney, Elstner Associates, Inc. (WJE) in 2015, a separation was identified between the steel sheet pile bulkhead and the rest of the structure along approximately one-quarter of the length of the wharf. The Port of Houston Authority (PHA) engaged WJE, with Lymon C. Reese & Associates (LCRA) as a sub-consultant, to further investigate and evaluate the significance of this finding. LCRA prepared numerical models and field tests for evaluating present conditions of the wharf designed and built in 1948 with major strengthening in 1969. Models assumed nonlinear soil-structure interaction and accounted for degradations of steel piling. Loadings included combinations of axial live loads from port operations (crane, rail, storage) and from design vessels as well as those from soil overburden. A conceptual strengthening for the foundation system was also evaluated and proposed along with the approximate construction costs.

Structural and Geotechnical Review and Retrofit of Manchester Wharves 2 & 3, Port of Houston

Manchester Wharves 2 & 3, Port of Houston, Texas
Wiss, Janney, Elstner Associates, Inc. & Port of Houston Authority
2015 to 2016
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. LCRA investigated critical structural elements that would be affected by the new dredging plans: original wood piles supporting the Relieving Platform, the wood bulkhead that retains soils for both structure levels, and the anchor tieback of the Relieving Platform earth-retaining wall. 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. LCRA prepared numerical models and field tests for evaluating present conditions of these wharves. Models assumed nonlinear soil-structure interaction and accounted for assumed degradations of pile foundations (verified with field investigations). Loadings included combinations of axial live loads from port operations (crane, rail, storage) and those from soil overburden behind the retaining structure, and as well as those from vessels mooring and passing. A conceptual strengthening for the foundation system was also evaluated along with the limitation in operation and approximate construction costs.

Dolphin Replacement at Manchester Wharf 3, Port of Houston

Manchester Wharf 3, Port of Houston, Texas
Wiss, Janney, Elstner Associates, Inc. & Port of Houston Authority
2016
One of the mooring dolphins, which consist of a 30-inch OD vertical steel pile and two 16-inch OD batter piles, was damaged due to a mooring incident. Wiss, Janney, Elstner Associates, Inc. (WJE) invited Lymon C. Reese and Associates to work on a proposal for replacement of damaged dolphin. Based on the field inspection, the top of the damaged dolphin was pushed several feet into approximately the northwest direction and the east batter pile touched the nearby pile which is supporting the catwalk between Manchester Wharf 2 and Manchester Wharf 3. After analytical studies based on the loads, pile properties, subsurface conditions, the damaged dolphin could not be repaired and should be removed by cutting the piles at the mudline. A replaced dolphin with new vertical and battered piles was installed at nearly the same location.

Structural Design of Pile Foundations for Jericho Turbine Wind Farm

Lambton County, Ontario, Canada
CWE Consultants, ULC
2014
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 soil-structure-interaction analysis for the pile group consisting of steel H-piles with 6 diameters of clear spacing in a two-circular configuration. The rotational stiffness and translational stiffness were analyzed to meet the turbine supplier requirement.

Conceptual Study of Medium and Long Term Development Facilities for Coveñas and TNP Oil Terminals in Colombia

Port of Cartagena, Republic of Colombia
Gault International and Ecopetrol
February 2010 to April 2010
Engineers from LCR&A formed part of an engineering team that performed an in-depth review and analysis of the Ecopetrol S.A. petroleum export and import facilities at Coveñas and Terminal Néstor Pineda (TNP). The objective was to assess the capabilities of the current facilities to determine the bottlenecks and upgrades needed to support a future export of 1 million barrels of crude oil per day and facilitate the exports/imports necessary to support expanded operations at the Cartagena refinery. The analyses performed consisted of hydraulic analyses of the Coveñas and TNP installations, tanker traffic analysis at both facilities, and simulations of export operations at both facilities. Solutions and cost analyses were provided for both facilities.

Preliminary Structural and Geotechnical Design of Foundations for Tension Leg Platforms in the Browse LNG Development

Offshore Western Australia
Wison Floating Systems (Woodside Energy Ltd)
August 2010 to October 2010
A combined gravity/suction base was proposed for the tension leg platforms (TLP) for the Brecknock and Calliance Dry Tree Units, with a center caisson and six other caissons laid out around the central caisson in a hexagonal pattern. The caisson diameters were designed at 12 m with also 12-m skirt length around each caisson. Three levels of load were evaluated: operating, extreme, and survival with respective safety factors of 2.0, 1.5, and 1.0. The base was analyzed for its load carrying capacity, installability, and settlement and consolidation considerations. In general, conservative soil properties were selected because of the significant uncertainty inherent in the calcareous silts at the site.A preliminary front-end engineering design has been performed for the foundation structure in this project. Four controlling environmental loading demands to the foundation system were selected for these preliminary analyses. A suitable foundation system was proposed for evaluations of overall impact in costs. Sizes, welds and layout of main structural elements were also evaluated for purposes of constructability (fabrication).

Ensenada Container Terminal Expansion

Ensenada, Baja California, Mexico
Hutchison Port Holdings. Ltd.
June 2008 to December 2008
Complete design of a container terminal expansion including full set of plans and specifications, material takeoff and preliminary costing. The project consisted of a 300-m quay expansion (to be built in two phases) designed to operate PostPanamax vessels of up to 140,000 DWT, 45-m beam, 347-m length and 14-m draft.The main structural system of the quay was designed with a grid of 1.45-m OD shafts with deep connecting beams in both orthogonal directions and a 45-cm slab. The seismic design followed the two-event guidelines normally used in the Port of Los Angeles for operational and contingency level earthquakes.

Lázaro Cárdenas General Cargo Terminal

Lázaro Cárdenas, Michoacán, México.
Terminales Portuarias del Pacífico, S.A.P.I. de C.V.
December 2007 to May 2008
Complete design of a general cargo terminal including a full set of plans and specifications, material takeoff and preliminary costing. The project consisted of 175-m quay to operate Panamax, PostPanamax and Capesize vessels of up to 200,000 DWT, 44-m beam, 325-m length and 16-m draft.The main structural solution for this project consisted of a front 1-m width diaphragm wall of 30-m length and a rear 1-m width diaphragm wall of 25-m length. Some intermediate rows of drilled shafts of 1.4-m OD were used in between the diaphragm walls. Connecting elements were beams of up to 2-m depths and 40-cm slab. Seismic loads included the inertial forces arising from the retained soils on the back side of the diaphragm walls, as well as those from the large 5 ton/meter square of live loads in the storage yard near the quay.

Finite Element Modeling of the Cadet Chapel at West Point

West Point, New York
John P. Stopen Engineering Partnership
November 2006 to January 2007
LCR&A conducted a three-dimensional modeling of the structural components of the Chapel.For the project, LCRA prepared the geometric model based on the original plans (from the early 1900s) and recent photographs of the structure. The finite-element model was generated using the three-dimensional finite element software AMPS (Advanced Multi-Physics Simulation). The full model of the structure has over 1 million elements.The walls of the building had up to 4-ft (1.22 m) thickness in some areas and were composed primarily of limestone, local stone (granite), and clay brick. Other materials used in the model were concrete for main-supporting columns and a different model for the Guastavino vaulting (composed of three layers of bricks). Static as well as modal analyses were carried-out.

Study of a 35-Story Residential Condominium Tower Using 3-D Finite Element Analysis

Phoenix, Arizona
Speedie and Associates
August 2005 to October 2005
LCR&A conducted advanced numerical modeling for investigating the behavior of the proposed foundation for a 35-story residential condominium tower. The foundation plan of 134.5 ft by 137.8 ft (41 m by 42 m) includes 41 drilled shafts for foundation walls and columns, and a mat for the core wall. LCR&A proceeded to study the behavior of foundations by using a three-dimensional, finite-element model. The model was analyzed using static loading based on linear-elastic behavior of the system.Solid elements were used to construct the finite element model of the total system, which includes drilled shafts, the mat, and the supporting soil layers. The model considered sufficient distance from the mat foundation to the outside boundary of soil. Using the three-dimensional finite element model, displacements (total settlement and differential settlement) of the mat foundation in the elastic layered-soil system were analyzed under different load conditions. Two different foundation configurations were considered for this study.
The proposed tunnel is located at approximately 50 to 60 ft below the existing ground surface. The tunnel is also located in the vicinity of the Colorado River and Barton Creek. The bottom of the lift-station wet well, drop shaft, and manhole are at 55 ft to 60 ft below the grade. LCR&A provided the complete structural design and detailing for a lift-station wet well and a valve vault near Dawson Road. The lift-station wet well is a reinforced concrete structure in a circular shape with the total depth of approximately 60 ft. LCR&A also provided detailed designs for the removable roof slab, which can accommodate the access hatches at the top.LCR&A designed a drop shaft for the upstream tunnel connection, which is approximately 60 ft in depth. The cross-section geometry of this shaft is a circular shape. LCR&A also provided structural design for the interior platform and other structural members required for this shaft, and incorporated provisions for the installation of a vortex drop structure.

Conversion of an Underground Storage Tank into a Foundation for a New Electrical Substation

City of Austin, Texas
Austin Energy and ABB
December 2002 to October 2003
Austin Energy decided to decommission a fuel-storage tank at their Holly Street Power Plant in an environmentally sensitive part of the city. The area above the tank was urgently needed for new electrical facilities. The initial project concept was to clean the tank of fuel residue and then fill the tank with concrete. The approximate volume of the tank was 10,000 cubic yards. The time required for construction and the large number of concrete trucks rolling through a residential area were judged to be unacceptable, so alternate schemes were considered.The plan developed by LCR&A was to do the necessary construction above the tank after environmental cleaning and reinforcement of the tank roof, if permitted by the concrete quality of the existing tank. The plans for the original construction were examined, integrity testing of the strength of the internal columns was undertaken, and a model of the entire tank was made using three-dimensional finite element analysis. The decision was made to leave the tank in place, make necessary modifications of the tank roof structure, and to build the electrical facilities on top of the tank.Placement and loads from the electrical facilities were obtained. A geotechnical study was made and a design soil profile was developed. Further integrity testing of the concrete of the tank was undertaken, and a structural design was developed to strengthen the top of the tank that permitted the added loads to be placed anywhere on the tank roof. The result was a plan that minimized the environmental impact of the construction and resulted in the savings of both project schedule and budget as compared to filling the tank with concrete.

Design Review of Balboa Phase 3 Quay Structure

Port of Balboa, Panamá
Hutchison Port Holdings, Limited - Panama Ports Company, S.A.
August 2002 to November 2002
The Balboa Phase 3 Quay and Dredging Contract was a design-and-construct contract for approximately 270 meters of container quay and berth and approach dredging works. The original contract assumed areas of soil reclamation in the back side of the quay along with a rock-bund wall. A late design modification eliminated required areas of soil reclamation and associated bund wall.A preliminary structural layout was submitted by the Contractor, Hong Kong Dredging, Limited (HKD), for initial pricing purposes. The Employer, Panama Ports Company, S.A. (PPC), a subsidiary of Hutchison Port Holdings, Limited (HPH) and with agreements of HKD, contracted Lymon C. Reese & Associates (LCR&A) to perform a general design review that included evaluations of other design alternatives. The intention of the project was to obtain construction savings in direct costs and/or completion time, while not risking the integrity of the finished product.A general report addressed initial investigations, soil studies, previous projects in similar soils, observations on design requirements and criteria, proposed fenders, connections to existing structure, models for berthing and operating loads, and models for soil-structure interaction. A separate report addressed the results from three-dimensional dynamic models that were used to evaluate seismic and operating loading (including wind) in extreme quay configurations.

Design of Pipeline Bridges

State of Montana, United States
SEFBO Pipeline Bridge, Inc. - Humble, Texas
April 2002 to December 2002
Cable-suspended bridges of several different pylon configurations were evaluated for spans varying from 130 feet to 400 feet and for two different sizes of pipelines. The pylons consisted of tubular steel and wide flanges. End supports of the cables varied from backstays to stiff steel elements, based on allowances from right of way. Foundation varied from drilled shafts to large mats, according to soil profiles, access, and local subcontractors. Details were provided for lateral cables to resist wind loads and for detailing of the suspension system (strands, ropes, sockets, clamps, clips, clevises, and pipe seats).

Evaluation of Steel Connections for 345kV Transmission Towers

Austin-Bastrop, Texas
ABB Sistemas, S.A. de C.V., Nuevo León, México
February 2001 to March 2001
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 structural and foundation elements had to be revised under increased loads. Engineers from LCR&A analyzed the structural connections from the strengthened superstructure to the enlarged foundation. The design of the structural steel plates (size and thickness), bolt pattern for embedment into the foundation, and weld length of superstructure steel angles were analyzed with finite-element models.

Design of Oil-Mooring Facility for Tankers up to 250,000 DWT at the Dos Bocas Terminal in Tabasco, Mexico

Industrial Port of Dos Bocas, State of Tabasco, Mexico
PEMEX - Inopesa, Mexico City, Mexico
September 1998 to March 1999
Partners of LCR&A were contracted for the complete design and preparation of construction drawings for a complex project of an oil mooring facility at the existing Pemex facilities at the Dos Bocas Port terminal Complex in the Mexican state of Tabasco. The existing Dos Bocas Terminal Complex from Pemex handles near 45% of the petroleum traffic of the country mostly using a system of single buoys. The new design was intended to increase the efficiency of the oil-handling operations since it will located within the port basin and protected by enlarged breakwaters.The structural form of the breasting and mooring dolphins as well as that of the operations platform were fixed platforms with steel tubular members, similar to those commonly used in fixed offshore platforms. The project was delivered on time and budget along with approximately 80 sheets of plans and technical specifications.

Dynamic Studies for Bridges over Slaughter Creek on South First St. Extension Project

Austin, Texas
Pickett, Kelm & Associates, Austin, Texas
May 1999 to August 1999
The City of Austin plans to extend South First Street to FM1626, with crossings over two arms of Slaughter Creek, in the City of Austin, Texas. Twin bridges, each of approximately 40-ft in width and with equal spans of 110-ft in length are planned for each crossing. The bridges spanning the main arm of Slaughter Creek, in the southernmost end, will each carry a walkway on one of their sides. The walkway will be suspended from the outermost prestressed-concrete girders.Lymon C. Reese & Associates (LCR&A) was contracted by Pickett, Kelm & Associates (PKA) to investigate the dynamic response of the suspended walkway. Several linear-dynamic analyses were performed and results are reported in this document. Responses to roadway traffic and to vibrations induced by people were taken into account in the dynamic studies.

Conceptual Design for Bridges over Slaughter Creek on South First St. Extension Project

Austin, Texas
Dept. of Public Work and Transportation, City of Austin, Texas
June 1998 to February 1999
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 conceptual design for the bridge components in cooperation with the structural designers. LCR&A investigated structural alternatives of precast, prestressed U-beams and standard AASHTO I-beams. Alternatives were presented for different columns and bent caps. Options to enhance the structure by detachment of the pedestrian bridges were also investigated.

Retrofit of Transformer Foundation at Seaholm Substation Soft Limestone

Seaholm Substation, Austin, Texas
Austin Electric Utility Department; Austin, Texas
May 1997
The foundation for a 135-MVA auto-transformer of the Seaholm Substation consists of a 51-ft x 12-ft x 6-ft rigid slab resting on topsoil and two drilled piers, each with an outside diameter of 6 feet. A containment pond with an approximate capacity of 30,000 gallons surrounds the foundation. Damages were induced to both structures during a fire in February of 1997. Engineers from LCR&A were contracted to design the retrofit of the damaged foundation and containment slab structures. Compression tests were performed on concrete specimens drilled from various parts of the damaged structures. The report included petrographic, chemical, and scanning electron microscopy studies of the distressed concrete. Tension tests were performed on exposed samples of the reinforcing steel.

Design for Seismic Strengthening of a Communications Center in La Paz

La Paz, State of Baja California Sur, México
TelNor S.A. de C.V.; México City
February 1997 to March 1997
The “Central La Paz” building houses telecommunications equipment and antennas in charge of long-distance calls that are made from La Paz to the interior cities of the Republic of México and to foreign locations.The main structure is a five-story (55,000 ft2, 80-ft height) reinforced-concrete frame with unreinforced masonry infill wall panels. Overall structural stability during design-level earthquakes according to the 1994 Uniform Building Code were reviewed. Alternatives considered for the strengthening details were restricted by existing telecommunication equipment and limited-land access. Architectural requirements further limited the alternative for retrofit.

Design of Axial Load Test Structure for Steel Piles in Panama

General Cargo Pier; Chiriquí Grande, Panama
Dillon Construction, Inc.; Panama
January 1996 to March 1996
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 twin-bridge 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.Reaction beams with a recoverable system of high-strength reaction bars were designed for the axial load test of two 42 in. o.d. steel piles at the site of a proposed general cargo pier in the southern shore of the Laguna de Chiriquí, in the Atlantic Coast of Panama. The reaction beams were designed for maximum axial loads of 1,000 Tons on 29-ft spans. The complete reaction structure, including 240 ft length of 42-in. o.d. steel casings for the reaction shafts and 2,500-ft length of dywidag bars were designed to be recoverable.

Repair and Retrofit Design of Reinforced Concrete Shell Tower in Cancún

Cancún, State of Quintana Roo, México
Compañía de Teléfonos y Bienes Raíces S.A. de C.V.; México City
Teléfonos de México - TELMEX; México City
Dates: 1995The tower was originally designed with strict guidelines for architectural impact, since it is built in a very important tourism location of a resort city from México. Three reinforced concrete shells of paraboloid shape form the elevation of this 40 meter height tower supporting telecommunications antennas. The structure deteriorated due to the adverse environment of high salts and humidity, combined with low maintenance and poor initial construction practices. Located in an area of strong hurricane-strength winds, it became necessary to repair and design a retrofit since high percentage of the structural steel was already corroded. Members of LCR&A recommended repair methodologies and designed a structural strengthening alternative that involved placing carbon composite fibers around existing beams.

Strengthening of the Tijuana-Centro Communications Center

Tijuana, State of Baja California Norte, México
TelNor S.A. de C.V.; México City
1994 to 1995
The “Central Tijuana-Centro” building houses telecommunications equipment and antennas in charge of long-distance calls that are made from Tijuana to the interior cities of the Republic of México and to foreign locations.The main structure is a five-story (68,000 ft2, 80-ft height) steel frame building with unreinforced masonry infill wall panels. Overall structural stability during design-level earthquakes according to the 1994 Uniform Building Code were reviewed. Typical beam-column joint connection details between steel elements were checked against the most current (Emergency Technical Bulletin No. 2 from November 1994) American Institute of Steel Construction (AISC) guidelines that appeared after the January 1994 Northridge earthquake in the San Fernando Valley, Los Angeles, California. A large percentage of similar steel buildings with welded moment frame connections suffered structural damages during the mentioned earthquake and a few university research projects provided design, repair and strengthening guidelines.

Preliminary Design of Retaining Walls for Highway Projects

San Antonio, TX
Unitech Consulting Engineers
1994
Members of LCR&A performed most of the study and preliminary design of piles used for retaining walls in highway projects for the city of San Antonio, Texas. The designs involved several retaining wall heights and pile configurations. The pile caps were designed with strut-and-tie structural models and the retaining walls were designed using prefabricated reinforced concrete panels.

Strengthening of the Tepic-Cultura Communications Center

Tepic, State of Nayarit, México
Compañía de Teléfonos y Bienes Raíces S.A. de C.V.
Teléfonos de México - TELMEX
Dates: 1994The “Central Tepic-Cultura” building houses telecommunications equipment and antennas in charge of all long-distance calls made from Tepic, the capital city of the state of Nayarit in México.Original designs of the main building were from the mid 1970’s. The principal structure is composed of a seven-story (50,000 ft2, 130 ft height) reinforced concrete frame building with unreinforced hollow masonry wall panels in most external facades. The existence of several cracks in beams of the superior floor levels as well as in some wall panels raised the owner’s interest in contracting some of the members of LCR&A to perform several structural checks of safety. A strengthening design was prepared reinforcing outer facades of the existing building with steel bracing and steel jacketing neighboring columns. The new foundation system was composed of several drilled shafts with special footings to tie with the existing foundation system.

Strengthening of the Coatzacoalcos Communications Center

Coatzacoalcos, State of Veracruz, México
Compañía de Teléfonos y Bienes Raíces S.A. de C.V.
Teléfonos de México - TELMEX
Dates: 1994The “Central Coatzacoalcos” building houses telecommunications equipment and antennas in charge of all long-distance calls made from Coatzacoalcos, a port city of the state of Veracruz in southern México.Original designs of the main building are from the late1960’s. The principal structure is composed of a seven-story (49,600 ft2, 130 ft height) reinforced concrete frame building with unreinforced hollow masonry wall panels in most external facades. The building location on a hurricane wind as well as possible earthquake zone produced concerns to check the structural design and produce retrofit alternatives. A strengthening design was prepared reinforcing outer facades of the existing building with steel bracing and new steel columns. Eccentric bracing were used to avoid interference with existing telephone line panels that were difficult to move. Heavy reinforced concrete jackets were used in some beams and columns of the bottom floor. The new foundation system was composed of several drilled shafts with special footings to tie with the existing foundation system.

Strengthening of the Estrella Communications Center

Iztapalapa, México City
Compañía de Teléfonos y Bienes Raíces S.A. de C.V.
Teléfonos de México - TELMEX
Dates: 1993The “Central Estrella” building houses telecommunications equipment and antennas in charge of calls that are made from México City to the interior cities of the Republic of México. Over 15,000 calls are channeled through this building during a normal day of operation.This seven-story (44,000 ft2, 125 ft height) reinforced concrete framed building was designed in the early seventies. Although it suffered only minor damages during the great Michoac‡n Earthquakes of 1985, new code requirements for the city called for a structural evaluation of its safety. Previous owners contracted a new study that was delivered in 1989. As the work for this strengthening scheme progressed through the foundation, new private owners asked associates of LCR&A to evaluate the original building, its recently strengthened foundation system, the planned superstructure solution, and possibilities for any other alternative strengthening designs for the superstructure. Several investigations and analysis were performed and an alternative solution based on a combination of stiffening members and prescription for energy dissipation schemes was presented. A full set of specific detailed drawings, a book of construction specifications, and a summary report were prepared. Considerable savings of construction costs were incurred by the new owner.

Strengthening of the Tuxtla II Communications Center

Tuxtla Gutiérrez, State of Chiapas, México
Compañía de Teléfonos y Bienes Raíces S.A. de C.V.
Teléfonos de México - TELMEX
Dates: 1992The “Central Tuxtla II” building houses switching equipment and operators in charge of all calls that are made from the city of Tuxtla Gutiérrez (capital of the State of Chiapas) to México City and to interior cities of the Republic of México. This two-story reinforced concrete framed building was designed in the late sixties. A 50 meters (160 ft) height metallic telecommunications tower is located on top of the concrete structure. Several cracks were observed on the columns underneath the tower. The observation of these cracks combined with the building location in a severe seismic zone generated a concern to the owners. The structure was studied in its existing condition and in a few possible strengthened configurations. A solution involving the addition of deep foundation members, and concrete jacketed columns and beams was prepared by associates of the LCR&A team. Complete studies of soil-structure interaction were necessary. A set of construction drawings, specifications, and a final report were also provided to the client.

Strengthening of the Tuxtla I Communications Center

Tuxtla Gutiérrez, State of Chiapas, México
Compañía de Teléfonos y Bienes Raíces S.A. de C.V.
Teléfonos de México - TELMEX
Dates: 1991 to 1992The “Central Tuxtla I” building houses telecommunications equipment and antennas in charge of all calls that are made from the city of Tuxtla Gutiérrez (capital of the State of Chiapas) to México City and to interior cities of the Republic of México. This seven-story (28,000 ft2, 125 ft height) reinforced concrete framed building was designed in the late sixties. Its location in a severe seismic zone as well as its geometric configuration generated a concern to the owners. The building was studied in its existing condition and in several possible strengthened configurations. The close presence of neighboring structures further limited the possibility of alternative strengthening schemes. A solution involving the addition of deep foundation members, and a strengthened superstructure was prepared by associates of the LCR&A team. Basic studies of soil-structure interaction were necessary. A complete set of construction drawings, specifications and a final report were delivered to the client.

Study of the Container Terminal Wharf in the Port of Topolobampo

Topolobampo, State of Sinaloa, México
Ingeniería y Puertos S.A. - IPSA
Grupo ICA - Ingenieros Civiles Asociados
Dates: 1990The general contractor for the first container terminal wharf in the Port of Topolobampo, Pacific Coast, México, encountered several problems after the installation of over 400 reinforced concrete piles. Associates of LCR&A were consulted to determine the event that caused a general displacement of the head of the driven piles, the effect of the new pile geometry on the superstructure and for the normal operation of the overhead cranes, and the recommendation of any possible solution. Studies of the group of piles, laterally filled soils, soil-structure interaction problem using finite differences, and flat-slab systems using finite elements were performed. All these were done under a tight schedule since the construction operations continued during the project evaluation. A final report that included an alternative solution was presented to the client.

Design of Offshore Oil Mooring Facility

Puerto Libertad, Gulf of California, Mexico
Comisión Federal de Electricidad, C.F.E.; Puerto Libertad, State of Sonora, México
1982 to1983
The purpose of this offshore marine facility was to provide mooring and oil (“combust—leo”) unloading capabilities for tankers up to 50,000 DWT, to supply fuel to a nearby new power plant. The project consisted of the design of the mooring structure as well as an access bridge. The one-kilometer long bridge was necessary for the regular access of repair and maintenance vehicles, as well as to support the oil and power lines. The analysis included oceanographic studies, determination of storm waves, currents, winds and tides. For the analysis of the structures, problems of hydrodynamic soil—structure interaction, such as vortex and wave action on the piles-soils complex, were solved. Besides, the forces exerted by the oscillating ships due to wind, waves and currents on the main mooring and breasting dolphins, were calculated. A complete set of construction drawings, specifications and a final report were delivered to the client.

Design of Dry Dock for Major Shipbuilding Yard in the Port of Veracruz

Port of Veracruz, State of Veracruz, México
Astilleros Unidos, S.A.; México City
1981 to1982
Members of LCR&A provided the design for this major shipbuilding yard that provided México with the capability to build 50,000 DWT tankers for the Pemex fleet. The main structures of this project were the dry dock (drained and gravity alternatives), excavation scheme, foundations for the tracks of the large shipbuilding cranes and a pier for afloat repairs and finishing.The structural alternative selected (gravity dry dock), required the analysis and design of retaining walls, slabs, pump chambers and lock gates under a very large amount of combinations of loads, such as: ship weight, soil subpresion, earth pressure and water pressure all combined with flooding and draining of the dry dock; surcharges; and wind and seismic forces. The foundations for the large cranes were designed for extremely small settlement tolerances and the pier structure was designed to comply with strict water and land operation levels. The design of the dewatering system implemented for the main excavation was very complex since there were several soil types in the site. The soils at the site ranged from calcareous rock to sand, clays and city land fills. Complete drawings, specifications and a final report were delivered to the client. On the site consulting during the construction period was also provided.

Design of Syncrolift Shipyard

Ensenada, State of Baja California, México
Astilleros Rodríguez, S.A.
1980
LCR&A members designed this shipyard for the construction and repair of fishing boats with a Syncrolift vertical transfer system. Includes the design of reclaimed landfill, jetties, ship tracks elastic foundations, Syncrolift piers, mechanical installations and workshops. The tracks foundation and the Syncrolift dual piers structures were designed to comply with very strict tolerances for settlements and ship lifting p-delta effects, respectively. Complete drawings, specifications and a final report were delivered to the client. On the site consulting during the construction period was also provided.

Design of a Bulk Cargo Mechanized Pier in Pajaritos, Gulf of México

Location: Pajaritos, State of Veracruz, México
FERTIMEX; México City
1980
Bulk Cargo Mechanized Pier project, to handle urea and phosphoric rock and operate simultaneously two ore carriers of 40,000 DWT each. The pier structure was designed to sustain bulk cargo handling equipment (loading and unloading), as well as berthing impact loads, under poor soil conditions. A rolling dolphin was specially designed to help maneuver the large ore carriers in a small turning basing that imposed restrictions to the berthing operations. Includes electrical and cargo handling equipment installations. Complete drawings, specifications and a final report were delivered to the client.