TEXAS CITY CHANNEL DEEPENING A DESIGN-BUILD FIRST

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1 TEXAS CITY CHANNEL DEEPENING A DESIGN-BUILD FIRST Larry A. Wise, P.E. 1 and Philip J. Burgmeier 2 ABSTRACT Chosen for its efficient delivery process, the Texas City Channel Deepening Project marks the first time that the USACE utilized the design-build method for a major navigational improvement dredging project. Moffatt & Nichol along with HVJ Associates, as engineers and designers of record, and Weeks Marine, Inc., as constructors, formed the design-build team for dredging and placement, modification of existing placement area levees, and onsite construction support. The 11 km (6.75 mile) long Texas City Channel connects the Port of Texas City to the Houston-Galveston Channel and the Gulf of Mexico. The channel serves the 10th largest port (in terms of tonnage) in the country. Weeks Marine, Inc., under contract to the U.S. Army Corps of Engineers (USACE) Galveston District, deepened the channel from 12.2 m (40 feet, ft) to 13.7 m (45 ft). The project consisted of maintenance dredging followed by dredging for the deepening, which produced approximately four million cubic yards of dredge material. Approximately 690,000 m 3 (900,000 cubic yards, cy) of maintenance material was used to renourish an existing recreational beach on the Texas City Dike. The new work material was used to construct perimeter levees for 273 hectares (685 acres, ac) of new intertidal wetlands near the Texas City Channel and adjacent to Pelican Island, which will be filled over time with approximately 7.6 million m 3 (10 million cy) maintenance dredged material. These new levees were armored with rock to protect them against waves. Design-build is a new methodology for the U.S. Army Corps of Engineers for navigation projects. Some of the highlights and lessons learned from the contractor s and engineer s perspectives will be discussed. Keywords: Dredging, beneficial uses, levees, design build. INTRODUCTION The design-build procurement and construction methodology currently accounts for more than 1/3 rd of private sector, non-residential construction and is growing in importance for public sector work in the United States. Under the traditional design-bid-build methodology the design work is completed by the owner, or the owner s engineer, and then a complete set of construction documents (plans and specifications) are bid on by the construction contractor. In the design-build methodology the owner provides a conceptual level (typically 30% complete) design along with functional requirements for the project. The construction contractors then team with an engineer to serve as the designer of record and complete the construction documents. The owner maintains involvement, either directly or using an outside owner s engineer, to ensure that the construction documents and constructed project meet the needs and intent of the project. The design-build methodology offers several potential advantages to the owner and constructor. These include: Potential to expedite project schedule by completing design tasks, particularly for later portions of the job, during construction. Ability of the contractor to modify design elements, within functional requirements of the owner, to better suit the contractor s available equipment and preferred methodologies. Potential for alternative design concepts to be used which may result in cost or schedule savings. Increased participation of the engineer throughout the construction process. 1 Sr. Coastal Engineer, Moffatt & Nichol, Richmond Ave. Suite 200, Houston, Texas 77042, USA, T: , Fax: , lwise@moffattnichol.com. 2 Project Manager, Weeks Marine, Inc., 304 Gaille Drive, Covington, Louisiana 70433, USA, , , pjburgmeier@weeksmarine.com. 128

2 Decreased risk for the owner due to designer and constructor being joined under one contract, taking the owner out of the middle of disputes. The design-build methodology has recently begun to become used in the U.S. dredging market. Several private marine terminals have used the methodology, including several liquefied natural gas terminals on the Gulf Coast which Weeks Marine, Inc. and Moffatt & Nichol have been involved with either as a team or individually. The Texas City Channel deepening project was funded, largely, under the American Recovery and Reinvestment Act of 2009 (ARRA). Due in part to the desire to expedite construction of the project the U.S. Army Corps of Engineers chose to use the design-build methodology. This is the first time a major navigational improvement dredging project has been procured by the Corps under this methodology. This paper will summarize the project and examine some of the differences between design-build and traditional design-bid-build methodology as pertained to the project as well as discuss some of the lessons learned from the perspective of the design-build team of Weeks Marine and Moffatt & Nichol. PROJECT BACKGROUND AND OVERVIEW Originally created in the 1890s and reaching its present configuration in 1967, the 11 km (6.75 miles) long Texas City Channel (Figure 1) is a federally maintained, deep-draft navigation channel serving the deepwater Port of Texas City. The Port of Texas City is 11 km (7 miles) from Galveston and 18 km (11 miles) from the Gulf of Mexico. The Port of Texas City is currently the 10th largest port in the nation in terms of tonnage, with 48 million tonnes (52.6 million short tons) throughput annually. Key commodities passing through it include crude oil, gasoline, diesel, and jet fuel. The principal purpose of the Texas City Channel project (Figure 2) was to deepen the 121 m (400 ft) wide channel from 12.2 m (40 ft) to 13.7 m (45 ft). This required dredging of approximately 1.9 million m 3 (2.5 million cy) of new work material. This newly dredged material was used to construct approximately8.8 km (29,000 linear ft, lf) of new levees to create new dredged material placement areas in open water. Placement area SPPA 2, 59.5 hectares (147 ac), was adjacent to existing placement areas 5 and 6. Placement areas SPPA 3 through 5, totaling 165 hectares (408 ac), are a new island just east of existing placement area 5 and 6. The fifth placement area was constructed on the west side of Pelican Island and totaled 40.9 hectares (101 ac). Placement areas SPPA 2 and Pelican Island were constructed in relatively shallow water ranging from zero to approximately 2 m (6 ft) depth. SPPA 3 through 5 was constructed in slightly deeper water averaging approximately 2.4 m (8 ft) depth. Over time, these placement areas will be filled with dredged material from channel maintenance to create approximately 263 hectares (650 ac) which will eventually be converted to emergent marsh. The project also included levee raising for an existing upland placement areas 5 and 6 in order to accommodate approximately 0.4 million m 3 (0.5 million cy) of maintenance dredged material. The contract also included the repair of shore protection, both rock riprap and concrete block mattresses, damaged by Hurricane Ike in Another approximately 0.8 million m 3 (1 million cy) of maintenance dredged material was placed on to the beach on the north side of the Texas City Dike to re-nourish the beaches and help repair damages from Hurricane Ike. 129

3 Figure 1. Overview of project area including existing placement areas 5 & 6 and new placement areas SPPA 2, and SPPA 3-5 (SPPA 1 & 1A were not included in the contract and Pelican Island placement area is modified from the original RFP configuration) Figure 2. Typical cross-section for channel deepening (previously removed maintenance material shown as cross-hatched). 130

4 SELECTION The Texas City deepening project was initially studied and authorized (for a 15.2 m (50 ft) depth) by the Corps in 1982 but was never constructed. In 2001 the City of Texas City, the local sponsor, reactivated the project and the Corps completed a limited re-evaluation in The initial design work was completed by the Galveston District and documented in the Final-Draft Engineering Appendix dated The conceptual design, 30% complete, was by the Galveston District and released for bidding purposes in June of The Corps used a two phase best value selection process through a Request for Proposals (RFP). The RFP process originally included 30 days for the first phase and 30 days for the second phase. In Phase 1 of the RFP, design-build teams submitted certain specified performance capability and qualifications information, demonstrating their capability and capacity to successfully execute the design-build construction contract. The Corps used the Phase 1 submittals to qualify firms who were requested to submit a follow-on Phase 2 proposal. Selection was based on: business management plan (including organization, quality control, health and safety, and personnel); specialized experience; past performance; key project personnel capabilities and experience; and, financial capability. After notification of qualified firms from the Phase 1 process, approximately three weeks were initially allotted for preparation of the Phase 2 RFP, although through amendments this was extended to approximately seven weeks. In Phase 2, the selected teams submitted a preliminary technical-design, the remainder of the performance capability information, a preliminary schedule, and a price proposal. The Phase 2 selection was based on a combination of price and non-price factors. Price items included a mix of unit price and lump sum bid items. Price was not rated but was evaluated for reasonableness. Non-price factors included: qualifications submitted in Phase I; technical factors based on design-build teams proposed approach for each of the project elements including design approach and data collection, equipment, means and methods, use of available materials, and environmental protection; submitted deviations, exceptions, and assumptions; preliminary schedule and resources commitment; and, small business utilization. The non-price factors were evaluated based on basis of design sufficiency, innovation, reasonableness of their approach given the site conditions, efficient use of dredged material to construct the placement areas, and ability to utilize on-site materials to rehabilitate existing and construct higher levees. The conceptual level (30%) design was provided by the Galveston District as part of the Phase 2 RFP package. Requirements for design, coordination, safety, environmental protection, and quality control were conveyed in technical specifications (Division 01). The design consisted of a set of conceptual design drawings which included plan view layouts and typical sections for each required design element (the maintenance dredging, the levee raising for the existing placement area, the repair of shore protection for the existing placement area, the new work dredging, and the new beneficial use placement areas), and geotechnical boring logs and limited testing results in the project vicinity. Additional data was also provided as part of the Phase 2 package, either attached or as 131

5 amendments, including a condition assessment of the existing placement area, channel after dredge (AD) surveys from recent maintenance dredging events, the General Design Memorandum, General Reevaluation Report and Environmental Assessment, and the Shoal Point Container Terminal Environmental Impact Statement. The scope of work for the project and technical requirements were provided in a Statement of Work (Section ). The scope of work section defined the functional requirements for each project element. The general technical requirements were conveyed in prescriptive statements similar to technical specifications in a design-bid-build contract. The design-build process differed from typical design-bid-build methodology in several key points: A significant proposal outlining the design-build team s approach, resources, and schedule was required; The engineer (designer of record) was involved in the bidding process and modifications, exceptions, deviations, and assumptions as part of a pre-award design were requested; The design-build team was provided opportunity to collect additional field data as part of the pre-award design; The pricing was based on conceptual level design, not final design documents; The owner provided design information from several extensive documents covering several years of the evolution of the project. Based on the Weeks Marine and Moffatt & Nichol experience from this specific project a number of lessons were learned in regards to the selection phase in a public works, design-build dredging project including the following: Owner should provide sufficient time for field data collection, such as geotechnical boring and/or geophysical data, if such data is believed to be required for the pre-award design, otherwise only information provided in the RFP package can be used potentially resulting in risks for the owner, designer, and constructor. Owner should provide sufficient time for significant pre-award design, including optimization to functional requirements, and pursue innovation in design during the RFP process. As a part of this, the owner should consider a design stipend to all teams selected through the qualification process in order to offset costs and encourage more extensive pre-award design. To the extent reasonable the owner should provide functional requirements for project elements rather than prescriptive technical requirements. Where prescriptive technical requirements are provided it is perceived that these are limitations on the design. The owner should try to provide a clear delineation between what elements of the design are fixed and what elements the design-build team is allowed to modify. The owner should provide as much information as possible on the project; however, sometimes providing extensive documents from prior phases and evolutions of the project results in contradictory and/or confusing information which the design-build team is unsure of how to deal with. Information provided in the selection process should be clearly delineated between requirements and general background information. DESIGN Moffatt & Nichol served as the designer of record for civil engineering on the project along with HVJ Associates as designer of record for geotechnical engineering. The detailed design work for the project began after award in November The project was divided into four design packages which were completed sequentially: Package 1 maintenance dredging and improvements to existing placement areas 5 & 6, Package 2 shore protection rehabilitation for existing placement areas 5 & 6, Package 3 new work dredging and construction of SPPA 2 and SPPA 3 through SPPA 5, and Package 4 new work dredging and construction of Pelican Island placement area. The design work commenced with collection of topographic surveys for the existing placement areas 5 and 6 and hydrographic surveys of the channel and new placement areas. Soil borings were conducted for the placement area 132

6 5 and 6 levees where no prior borings were provided. Other data collection efforts included subsurface utility location and magnetometer surveys for both dredging and levee construction areas. For each design package the engineering design was finalized through various analyses. For each design package a set of design drawings and technical specifications was prepared. Additionally a supplemental design documentation report was prepared documenting analyses performed and any design assumptions. For each package; 60%, 90%, Final, and Issued for Construction, sets of all design documents were prepared. Each set was submitted for Corps review and approval. In addition to formal submittal reviews, there was regular coordination between the design-build team and the Galveston District both formally through the submittal of Requests for Information (RFI s) and informally through teleconference and progress meetings. For the maintenance dredging, Package 1, the analysis included an estimation of the additional levee height required to offset the material to be placed in the placement area. The calculation of the required levee raising resulted in a lower crest elevation than originally shown in the RFP drawings. Geotechnical analysis of the levee stability was also performed and resulted in offsetting of the levee and creation of an exterior bench in two areas. The movement of the levee centerlines was necessitated by USACE geotechnical guidelines for the required factor of safety based on slope stability models; however, based on normal design procedures for the Galveston District these changes may not have been made as the owner may have been willing to accept a higher risk (lower safety factor) rather than moving the levee which may have other unaccounted for risks. As discussed below, the movement of the levees required significant additional effort for the contractor and impacted the critical path schedule for the project. For the rehabilitation of the existing shore protection, waves were estimated for both wind generation under various return period winds and for ship generated waves and propeller wash. These were used to confirm the sizing of the existing rock riprap and concrete block mattresses. The rock riprap was designed to be repaired with existing riprap supplemented with additional material. The concrete block mattresses were completely replaced. The levee raising for the existing placement areas 5 and 6, Package 1, was commenced while the subsequent design Packages 3 and 4 were still in progress. A design for the new work dredging and hydraulic placement of levees was prepared which was optimized for Weeks Marine s proposed equipment and methodology. A plan for utilization of the new work dredged material was developed in a cooperative effort between the engineer and contractor. Geotechnical analyses were performed to determine slope stability and anticipated short-term displacement of bay bottom mud and long-term settlement. The design work included estimation of water levels, winds, and wind generated waves for various return period storms along with ship generated waves. This analysis was used to develop the rock riprap armor details (Figure 3). The riprap cross-section originally provided in the RFP package was used as the basis of bidding and optimization of the design was required to maintain the quantity of riprap while meeting the functional requirements of the project. The total capacity of each placement area was also confirmed in the final design. Figure 3. Typical cross-section for levees and armoring (dimensions in ft, 1 m = ft). For the Pelican Island placement area, Package 4, the levees alignment was modified to better follow existing bathymetry contours and to optimize for placement of dredged material via shore pipe (Figure 4). The realigned levee did not contain right angle turns that would have been difficult for shore pipe placement. It also followed an existing ridge and moved the levee centerline away from the Gulf Intracoastal Waterway, decreasing the likelihood 133

7 of interference of shipping during construction. During construction of the southern terminus of the levee a previously undetected pipeline was discovered which necessitated the further realignment of the last 300 ft of the levee. Figure 4. Re-aligned Pelican Island placement area levee (dimensions in ac, 1 hectare = 2.5 ac). The conceptual design for the beneficial use placement areas called for construction of overflow weirs through the levee at the time of construction. In prior similar designs in the area weir boxes have typically been used and exterior exchange weirs have been installed after the placement areas have been filled with maintenance dredged material. The weir lengths for the various placement areas were designed based on USACE engineering manuals. A change to the original design which occurred during the construction process was to change the overflow weirs from concrete block mattresses to rock riprap. This change significantly simplified the construction process, since the rock riprap was already being used on-site, and eased sequencing requirements. Additionally, it alleviated the need to place a crane on the levee crest to offload and place the mattresses on the weirs. As part of the proposed design change, Moffatt & Nichol created a numerical model (in the DHI MIKE21 modeling system) of the overflow weirs to assess anticipated flow velocities over the weirs and the potential differences in hydraulic exchange due to differences in friction between riprap and concrete block mattresses (Figure 5). The model was based on simplified principles to allow rapid assessment of flow velocities for long time-series as well as storm conditions. 134

8 Figure 5. Numerical model results for overflow weir showing color coded velocity vectors (red is 2 m/s, 6.6 ft/s). Due to the differences between typical design-bid-build and design-build methodologies, there were a number of unique aspects to the design process during this project including: Field data for design was collected after contractor s submission of bid, resulting in some additional risk for the constructor as prices were already fixed; Geotechnical data supplied by owner was used for design purposes, whereas generally data is only used by the contractor to determine means and methods and anticipated production rates; The design work was part of the overall project schedule, requiring both the engineering work and review times to be accounted for on the critical path schedule; There was regular coordination between the owner, engineer, and constructor throughout the design process, whereas often the constructor is not present during this coordination; and, The design was tailored toward the constructor s equipment and methodology and constructability for the specific contractor was considered throughout the design process; Based on the experiences of the design-build team on this specific project, the following lessons learned are recommended for consideration: Any data supplied during the RFP process will likely be relied upon for design, particularly if there is insufficient time during the selection process to collect and analyze additional data; As geotechnical data will be relied upon for design, not just constructability and production rate considerations, full geotechnical reports should be provided as part of the RFP package, not just boring logs; The owner, or the owner s engineer, may have more leeway to accept risks during typical design-bid-build projects as any issues during construction can be dealt with if they occur, whereas in design-build the designer may be more rigidly bound to certain design guidelines; The design-build process does not necessarily consider timeline for future use of project features or incentivize consideration of future maintenance and full life-cycle costs in the design; Design reviews by the owner must be expedited to ensure that the project schedule is not affected; 135

9 The conceptual design provided as part of the RFP should be considered as open for modification, rather than treated as a rigid requirement, and any potential changes which the design-build team thinks may be beneficial to either party should be discussed even if they vary from the conceptual design; Close coordination and communication should be maintained between the design-build team and the owner throughout the contract to help ensure that functional requirements and technical criteria are satisfied. CONSTRUCTION Construction began on April 12, 2010 when the perimeter levee surrounding Placement Areas 5 and 6 was repaired, which was necessary because of damage sustained from Hurricane Ike. The levee was also raised to 6.4 m (21.0 ft) MLT (Mean Low Tide) to offset the maintenance material that was to be placed here later on in the project. The existing concrete mattress shoreline protection along the Texas City Turning Basin was then replaced. After a 75 day delay due to Emergency Berm construction following the Deepwater Horizon oil spill, a 76 cm (30 inch, in) hydraulic dredge and attendant plant were mobilized to the jobsite. Maintenance dredging began on August 17, First, 714,000 m 3 (934,000 cy) were placed in the two Beach Placement Areas adjacent to the Texas City Dike. Then 333,000 m 3 (435,000 CY) were pumped to Placement Areas 5 and 6 on Snake Island. Figure 6 shows dredging in progress. Figure 6. Dredging being performed in the Texas City Ship Channel, just south of the Texas City Dike. New work dredging began on September 19, 2010 and finished on July 9, Approximately 1.9 million m 3 (2.5 million CY) of new work material was dredged from the Texas City Channel. Since this quantity turned out not to be adequate to complete the levees additional material was dredged from the Shoal Point Borrow Area adjacent to the Texas City Channel (see Figure 1). This location was not included in the RFP so in order to evaluate the depth 136

10 at which material suitable for levee building began the area was sampled with a clamshell dredge. This information was combined with borings taken adjacent to the channel to calculate the required size of the borrow area. The SPPA 2 and SPPA levees were pumped into approximately 2 to 2.5 m (6 to 8 ft) of water via the spill barge shown in Figure 7. During construction of these levees erosion was a constant issue. This was dealt with by using material from the barge access channels, being dug adjacent to the placement area levees, as a sacrificial berm. In the spring of 2011, on the southern tip of SPPA 3-4-5, even this wasn t enough so barges and pipe were staged a few hundred feet south of the levee to act as breakwater. The pipe and barges protected the outside of the levee until it was armored early that summer. Figure 7. Spill Barge placing material for SPPA levee. Because of the shallow existing depths along the Pelican Island Placement Area, the levee was pumped with shore pipe and marsh buggies rather than using a spill barge. Erosion was never a problem at Pelican Island, but other challenges were in store. Most of the material for Pelican had to be pumped through a 4 inch screen, required due to potential Civil War era unexploded ordinance, which was constructed on the dredge s cutterhead. The screen served its purpose by stopping several cannonballs from being sent through the dredge pump and pipeline, but also managed to build up a lot of clay requiring frequent stoppages. In Figure 8 one you can see two cannonballs as well as some of the clay. There was also an unknown pipeline that was rediscovered on the south end of Pelican Island that required the levee centerline to be realigned as shown in Figure

11 Figure 8. Two of the cannonballs dredged up near the site where the USS Westfield sank during the Civil War. Following initial placement the levees were mechanically raised and armored on the exterior slopes. Once again outside circumstances interfered with the schedule as the rock was delayed 61 days because of the 2011 Mississippi River flood. Armor stone placement ultimately began on June 25, At this point the plant and personnel on site reached its peak. Dredges: 1 76 cm (30 in) hydraulic dredge in the channel, 2 clamshell dredges digging access lanes Boats: 7 tug boats, 5 crew / survey boats Miscellaneous Floating Plant: 8 deck barges, 3 anchor barges, 1 spill barge, 1 crane barge Land Equipment: 1 dragline, 3 marsh buggies, 7 excavators (some working off barges), 3 dozers Personnel: 86 total employees were working in two shifts as the dredging continued 24 hour / day 138

12 Figure 9. Mechanical levee raising with dragline above and excavator below. 139

13 Figure 10. Mechanical levee raising with clamshell dredge on left and riprap placement on the right According to the RFP Pelican Island s shore protection was designed to a higher specification than on SPPA 2 and SPPA This fact highlights a difference between the design-bid-build and design-build process in that the contractor is working off plans they had a hand in creating. Rather than keeping the same slope and requiring a thicker heavier stone layer on Pelican Island s levee the designer and contractor worked together to flatten the slope and keep stone specifications the same throughout the project. This allowed levee armoring to switch between locations without having to stage two different armor stone sizes. Since the stone was being sourced from Missouri this undoubtedly helped avoid stone supply problems. In addition to the armor on the levee s exterior slope there were also 9 weirs designed into the levees. One of the lessons learned from building these weirs is that the contractor and engineer need to continuously discuss how the design impacts constructability. Originally they were designed to be armored with concrete mattresses, but they were redesigned to be built out of stone of the same specifications used on the levee exterior slopes. Because the lines of communication were kept open the weirs were redesigned before construction began and had a chance to impact the schedule. Figure 11 shows a weir under a completed weir on SPPA Some of the differences from typical design-bid-build projects included: The designer was involved regular coordination meetings as well as in final inspection and approval process; Contractor is working off of plans and specifications that they had a hand in creating; Designer was involved in requests and recommendations for changes during construction due to issues which arose; and Task durations and equipment packages cannot be finalized until design work is completed. Below is a summary of the lessons learned during the construction phase of this contract: The contractor and engineer should continually discuss how the design is impacting or may impact constructability. The engineer should make regular site visits to see this first hand. The design-build method allows the contractor to modify the design of the project not just their construction methods. Contractors should use this to their benefit. Hold regular meetings with the engineer, owner, and contractor all in attendance. 140

14 Figure 11. Weir during construction (above) and shortly after completion (below). 141

15 CONCLUSIONS Design-build is likely to become increasingly prevalent in public sector contracts, including dredging. The methodology has several potential benefits to owners as well as constructors and designers. However, the difference from traditional design-bid-build and their ramifications must be considered at all points through the selection, design, and construction processes. Sufficient time and allowance of a stipend to defer costs for pre-award design should be provided during the selection process. Clear conveyance of functional requirements for the project is the cornerstone of the design-build methodology. Maintaining open and direct communications between all parties throughout the project is critical for success. CITATION Wise, L. A. and Burgmeier, P. J. Texas City channel deepening a design-build first, Proceedings of the Western Dredging Association (WEDA XXXII) Technical Conference and Texas A&M University (TAMU 43) Dredging Seminar, San Antonio, Texas, June 10-13,