A change in the code development process
Topics involving the building codes that govern structural engineering are frequently discussed in Structural Engineer. This is because I feel strongly that all structural engineers should fully understand how the building codes and design guidelines evolve and how practitioners will be affected; additionally, the frequency of code changes is at the top of the list of industry concerns for structural engineers.
ASCE 7-05: Seismic design of free-standing walls
Free-standing walls, typically of concrete or masonry construction, have numerous functions such as separating adjoining properties, screening service areas, and protecting pools. No permit or inspection is required for such walls 6 feet or less in height per the 2006 International Building Code (IBC) Section 105.2.
Reduce risk through proper hiring and managing construction administration documents
The mission of the Risk Management Program of the Council of American Structural Engineers (CASE) is to improve the practice of structural engineering by reducing the frequency and severity of claims. CASE members have been developing tools that make achieving this goal more manageable. All CASE member firms have access to these tools included with their membership. These tools have been developed using the 10 Foundations of Risk Management as a basis. These 10 principles form the foundation upon which a risk management plan can be built.
The 2009 International Building Code An overview of the structural changes—Part 2
The International Code Council (ICC) uses an 18-month code-development cycle and a three-year code-publication cycle. There were more than 350 proposed code changes to the structural provisions in Chapters 16 through 23 of the 2006 IBC. Of these proposed code changes, approximately 200 were successful and will be incorporated into the 2009 edition of the IBC.
Concrete products and services
The cement shortages of 2007 are behind us, and demand is currently down. However, the federal stimulus package is projected to increase demand for concrete and related products. In a response to an open invitation from Structural Engineer, a number of companies provided the following information about their products. Company web addresses are provided for immediate access to additional information. To participate in Structural Engineer Specifiers’ Guides, visit www.gostructural.com/specguide.
Shaking it up—Test to improve mid-rise, wood-framed building design
This summer the largest full-scale earthquake test ever attempted will take place outside of Kobe, Japan. The project, known as the NEESWood Capstone Tests, is led by Colorado State University in close technical collaboration with Simpson Strong-Tie and features a full-scale, seven-story, mixed-use condominium tower. The 40 foot by 60 foot building will be subjected to Japan’s massive E-Defense shake table, the largest in the world.
Tomorrow’s structural engineers: Leaders or followers?
Science, engineering, and technology advances during the next few decades will provide many opportunities for America’s engineers—structural engineers included—and a great promise for them to significantly influence the outcome of the coming years. This is true because engineers add value and engineering achievements are so uplifting to the human spirit.
Revitalizing Hollywood & Vine Innovative engineering provides solutions to complex challenges
Laser scanning 2.0 New laser models trump point clouds for roller coaster redux
Laser scanning is one of the most effective technologies for gathering dimensional information for project design. Accepted widely by the architectural, power, and oil and gas industries, laser scanning provides a faster, more complete and more accurate alternative to traditional data collection techniques. The significant benefits of laser scanning—including reduced costs, improved schedules, increased quality, and enhanced safety—are benefiting new industries.
Bracedframe steel structures 402 When and why frame action matters
Braced frames, including those that are to resist seismic or large wind loads, traditionally have been analyzed and designed as simple trusses with all joints pinned. However, braced frames using gusset plates are actually braced moment frames (Richard, 1986) because the presence of a typical gusset plate creates a joint zone even larger and more complicated than that of a moment frame connection (Walters et al., 2004). Full-scale tests of braced frames designed to resist seismic loads (Mahin et al., 2002) showed that the structural elements surrounding the braces created a moment frame that was the defacto "primary" lateral force-resisting element rather than the brace(s).
History repeats Screw piles come of age again
There’s an old saying that "history repeats herself." It seems that even in geotechnical engineering and foundation construction the adage is true. In the middle of the 19th century, screw pile or helical pier foundations became one of the most pre-eminent types of foundations used throughout the world. While the availability of labor popularized other foundation types for a while, the simplicity and effectiveness of screw pile techniques are once again creating demand.
Beware of low budgets
Since 1972, federal regulations have required qualification-based selection for federal projects requiring professional services such as architecture or engineering. The legislation had the effect of taking price out of the selection criteria, maintaining professional qualifications as the primary focus. This certainly seems logical, but what about our professional ethics that dictate our regard for public safety, duty to the client, and duty to the employer? Are we to believe that a low bid for a juicy project could somehow affect our professional judgment?
Water infrastructure funding increases
Last month on this page, I addressed the transportation funding aspect of the American Recovery and Reinvestment Act (stimulus bill). The poor state of bridges and roads, as well as the need to fund their maintenance, repair, rehabilitation, or rebuilding, is a hot topic these days and commonly discussed by President Obama, other politicians, and the press. Perhaps the reason that these facilities are targeted is because traffic congestion and road and bridge closings are something the public experiences and can relate to easily. Public approval for money going to their improvement is likely greater than for things underground, overhead, or intangible.
Noncompete agreements for engineering professionals
Noncompete agreements operate to restrict an employee from competing against his or her employer in the event that the employee leaves the company. These agreements are used to protect, among other things, customer lists and contacts, trade secrets, and certain intellectual and proprietary assets that an employee may learn about while employed with a company. The use of noncompete agreements for design professionals is increasing. In fact, the United States Chamber of Commerce suggests that employers ask "all engineers and drafting employees engaged in design or engineering work" to sign such agreements.
Constructability: The game changer
The American Institute of Steel Construction published the Constructability Design Guide (authored by Dave Ruby, founder of Ruby+Associates) in February 2009, a work that has been in progress for the last two years. The timing is ironic, with construction activity reaching the lowest levels most of us have seen in decades. But maybe the timing is perfect. When construction begins again, and it will, how will we as (civil) design engineers be called upon to do things differently? How will owner expectations change? How will project financing change and impact the role of the design and construction team?
Taking the plunge
A college buddy and I currently work for two firms in the metropolitan area, but we have remained close since graduating and recently met to discuss setting up our own firm. We have been out of school about nine years and both of us are licensed. I am more into the sales and management aspects of engineering while my friend is interested in the technical aspects of our work and is a genius when it comes to computers and automated design. Because of our complementary skill sets, we think we would make a good team. What steps do we need to go through to take the idea of starting our own firm from wishful thinking to reality?
How can GIS help develop a CIP?
With budgets being strained at every turn, municipalities and utility companies need to know that their Capital Improvement Plan (CIP) dollars are being spent in areas that will truly make a difference. So the first question becomes, "Where will it make the most difference, and where is my biggest need?"
Soil reinforcement, digitizing pen, economic resource, sound barrier, scanner, and web-based software
Soil reinforcement technologies brochure
Strata Systems, Inc., published a new brochure on its StrataSlope system that offers technical data and application references designed to help civil engineers, site developers, and construction firms identify available soil reinforcement technologies that address difficult geotechnical engineering challenges. StrataSlope uses Stratagrid, a geosynthetic, precision-knitted polyester geogrid, to create dimensionally stable steep slopes, embankments, temporary earthen walls, bridge abutments, levees, and segmental retaining walls. These mechanically reinforced structures can maximize the usable land for change-of-grade applications. According to the company, the StrataSlopes brochure showcases some of the most advanced and scientifically tested geogrid systems available across a wide range of soil reinforcement applications.
Strata Systems, Inc.—www.geogrid.com
Many companies took advantage of Environmental Connection (EC09), the annual conference and expo of the International Erosion Control Association (see page 40), to introduce their latest products and services for erosion and sediment control. Following are some of the products showcased at EC09. Additionally, in response to a request from CE News, other companies provided current information about their products. Company web addresses are provided for immediate access to additional information.
Large-block retaining wall cuts rain delays during site development
The smell of rain and diesel broke the stiff humid air over Placerville, Calif., on Nov. 4, 2008. Construction of the new Holiday Inn Express Gateway hotel on Highway 50 was just underway amidst the rain that began pummeling the western Sierra foothills. Richard MacFarlene, owner of Catamount Construction, began preparing the jobsite for mud. The project had been running on schedule and would have to be halted until the downpour subsided.
Build a committed, productive team
Civil engineering firms have been hit hard by the economic downturn. In many areas, development has slowed to a trickle, leaving many design and planning firms struggling. In an environment like this, it is essential for these firms to operate productively, and the key to productivity is building a team of people who love their jobs.
EC09 in review
The enthusiasm, sharing, learning, and networking enjoyed by attendees at Environmental Connection 2009 (EC09), the International Erosion Control Association’s (IECA) annual conference and expo, attest that the event was a resounding success. A variety of factors contributed to this success: Remodeled facilities and a new skybridge improved access to the spacious Reno, Nev., Convention Center; the educational program of peer-reviewed topics was of the highest caliber; and most importantly, the quality and engagement of attendees was the highest ever. Overall attendance numbers were down slightly, but exhibitors said that the attendees were the best quality group they have seen. EC09 drew 1,855 total attendees and 140 exhibitors, with most attendees spending more time in the trade show than in previous years.
Technology enables firm flexibility
Nathan Weber is an early adopter. He’s keenly interested in new technologies and eager to put them to work. For Weber’s company—Diamond Design and Land Surveying in Murray, Utah—the use of new technology has kept things hopping through the economic downturn. But that’s not just due to the fact that the firm owns the latest and greatest instruments. A big part of Diamond’s success has been the innovative ways in which it applies the new tools for its clients.
New tools for designing segmental retaining walls
Segmental retaining walls (SRWs) were introduced in the United States about 25 years ago, first in landscape applications and later as structural retaining walls. These systems have great advantages compared with other wall systems, and SRW unit versatility has broadened their use and innovation. SRW units are dry stacked (without mortar) and rely on a combination of mechanical interlock, unit-to-unit interface friction, or shear capacity and mass to prevent overturning and sliding. The units may also be used in combination with horizontal layers of soil reinforcement that extend into the backfill to increase the effective width and weight of the gravity mass.
Advanced wastewater treatment facility designed to protect freshwater springs
The Wakulla Springs, located near Tallahassee in the Florida Panhandle, is one of the world’s largest freshwater springs. But its shallow aquifer is particularly vulnerable to pollution from the chemicals used on lawns and in agriculture, stormwater runoff, and nitrates from wastewater treatment and septic systems. The city of Tallahassee’s main sewage and wastewater treatment plant, located adjacent to the springshed, is rated at 26.5 million gpd and uses an activated sludge process to produce secondary effluent. Most of the effluent is stored in onsite ponds and reused for spray irrigation on agricultural crops and pasture. Now, the city is investing more than $180 million to overhaul its wastewater facilities to advanced wastewater treatment standards.