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NSPE Code of Ethics Case Study (Oil Spill)
Peter has been working with the Bigness Oil Company’s local affiliate for several years, and he has established a strong, trusting relationship with Jesse, manager of the local facility. The facility, on Peter’s recommendations, has followed all of the environmental regulations to the letter, and it has a solid reputation with the state regulatory agency. The local facility receives various petrochemical products via pipelines and tank trucks, and it blends them for resale to the private sector. Jesse has been so pleased with Peter’s work that he has recommended that Peter be retained as the corporate consulting engineer. This would be a significant advancement for Peter and his consulting firm, cementing Peter’s steady and impressive rise in the firm. There is talk of a vice presidency in a few years. One day, over coffee, Jesse starts telling Peter a story about a mysterious loss in one of the raw petrochemicals he receives by pipeline. Sometime during the 1950s, when operations were more lax, a loss of one of the process chemicals was discovered when the books were audited. There were apparently 10,000 gallons of the chemical missing. After running pressure tests on the pipelines, the plant manager found that one of the pipes had corroded and had been leaking the chemical into the ground. After stopping the leak, the company sank observation and sampling wells and found that the product was sitting in a vertical plume, slowly diffusing into a deep aquifer. Because there was no surface or groundwater pollution off the plant property, the plant manager decided to do nothing. Jesse thought that somewhere under the plant there still sits this plume, although the last tests from the sampling wells showed that the concentration of the chemical in the groundwater within 400 feet of the surface was essentially zero. The wells were capped, and the story never appeared in the press. Peter is taken aback by this apparently innocent revelation. He recognizes that state law requires him to report all spills, but what about spills that occurred years ago, where the effects of the spill seem to have dissipated? He frowns and says to Jesse, “We have to report this spill to the state, you know.” Jesse is incredulous. “But there is no spill. If the state made us look for it, we probably could not find it; and even if we did, it makes no sense whatever to pump it out or contain it in any way.” “But the law says that we have to report…,” replies Peter. “Hey, look. I told you this in confidence. Your own engineering code of ethics requires client confidentiality. And what would be the good of going to the state? There is nothing to be done. The only thing that would happen is that the company would get into trouble and have to spend useless dollars to correct a situation that cannot be corrected and does not need remediation.” “But….” “Peter, let me be frank. If you go to the state with this, you will not be doing anyone any good–not the company, not the environment, and certainly not your own career. I cannot have a consulting engineer who does not value client loyalty.” What are the ethical issues in this case? What factual and conceptual questions need to be addressed? How do you think Peter should deal with this situation?
NSPE Code of Ethics Case Study (L’Ambiance Plaza)
L’Ambiance Plaza was to be a 16 story structure with 3 parking levels and 13 apartment levels. It was composed of two offset rectangular towers, separated by a construction joint at a central elevator lobby. Each tower was approximately 63 ft x 110 ft (19.2 m x 33.5 m) in plan. Typical floor to floor height was 8 ft – 8 in. (2.64 m). The structural frame had steel columns and 7-in. (178 mm) thick post-tensioned concrete flat plate floors. The flat plate floors were designed to be constructed by the “lift slab system.” The design used unbonded plastic-sheathed post-tensioning tendons in each direction. Tendons were banded within a strip along the column lines in the east-west direction and were distributed uniformly over the width of the bay in the north-south direction. Mild steel reinforcing was limited, consisting of small mats of #5 bars in the top of theslab at each column, 2 – #4 or #5 bars along slab openings and edges, and miscellaneous bars at locations of minor extent in, or adjacent to, pour strips and shear walls. Steel channel shear collars were provided at all column locations for load transfer and lifting operations. Lateral resistance in the completed structure was provided by two shear walls in each direction in each tower. These extended to two levels below the roof. For the top two levels, lateral resistance relied on frame action with rigid joints between steel columns and post-tensioned slabs. The building was founded on spread footings intended to be on rock. Ground level was up to 2 stories higher on the north side than on the south side. The unbalanced lateral earth pressures were supported by the building foundation walls and the shear walls.
Contract Documents
The Contract Documents were prepared by an architectural firm engaged by the owner-developer of the project. The architect retained a structural engineering firm that developed the basic structural design for the project and prepared the contract structural drawings and specifications. The contract documents recognized that the structural frame would be constructed by the lift-slab method. They did not contain certain important structural requirements and details because the project specifications required the contractor who was responsible for lift-slab construction to develop the slab post-tensioning design and details and the column connection design and details. The contract drawings show the type of system intended, namely steel columns and 7-in. (178 mm) thick flat plate floors with draped unbonded post-tensioning tendons, arranged in column strip bands east-west and uniformly distributed over the bay lengths north-south. No design was provided for the required post-tensioning reinforcement. The responsibility for this was given to the Contractor. The drawings also show the size and location of large slab openings for elevators and stairs and the arrangement of shear walls and other walls that are to be cast through floor slots after the slabs are lifted. Based on a schematic typical detail, the drawings indicate that east-west post-tensioning bands may be given horizontal sweep (offset) to accommodate openings, and that certain mild steel reinforcement is to be provided around the edges of slab openings. No information is given about the specific arrangement or design of post-tensioning reinforcement at the bays that contain large openings for elevators and stairs. Again this design responsibility was given to the contractor. The structural drawings show design requirements for shear walls. A note on a drawing states that: “shear walls shall be advanced to within 3 floor levels of the slabs being lifted” during construction. A schedule of column sizes, to be reviewed by the lifting contractor and increased, if necessary for stability and strength during erection, is included on the drawings. Minimum requirements for moment transfer through lifting collars also are given
NSPE Code of Ethics Case Study (Cypress Street Viaducts)
Collapsed section of Cypress Street Viaduct, 1989
In October 17, 1989 the Loma Prieta earthquake hit the San Francisco Bay area, causing over $12 billion in damages and claiming 64 lives. Over half the victims were on the Cypress Street Viaduct during the quake. What follows is an overview and analysis of the disaster, with reference to the materials and design features used in the construction of the viaduct. The knowledge gained from this tragedy has benefited subsequent structures not only in the technical data that it provided but in the research that such a public disaster is bound to initiate.
History of Bridge In 1949, the design of a new highway that was to service the City of Oakland, California began; by 1957, the construction of the Nimitz Freeway, or I-880, was complete (Yashinsky, 1998). A portion of the Nimitz Freeway that linked the I-880 to the I-80, known as the Cypress Street Viaduct, was a 2 km two-tier highway with five lanes per deck, and traffic flowing at ground level. The path that the Cypress Street Viaduct was required to follow resulted in certain portions of the bridge being constructed on soft mud; in much of the area, the bedrock was over 150 m below the surface (Yashinsky, 1998). The bridge was constructed using cast-in-place concrete with multi-celled reinforced box girders that typically spanned 80 feet (Moehle, 1997). At the time of construction, the California State seismic criteria required designing for a lateral force of 0.06 times the dead load (Yashinsky, 1998). Over subsequent years there was great advancement in both construction and earthquake engineering technology, and although new technology was becoming available, the Cypress Street Viaduct was not being properly restructured to withstand a large-scale earthquake. After a 1971 earthquake in the San Fernando Valley, the State of California initiated a two-phase program to increase the resistance of highways and bridges to earthquakes: Phase 1 involved strengthening the connections between elevated road ways and their support columns; Phase 2 was to strengthen the support columns themselves (Doyle, 1989). While the structure was retrofit with cable restrainer units in 1977, Phase 2 was never carried out on the Viaduct (Yashinsky, 1998).
The Loma Prieta Earthquake