Two important steps in the design of concrete structures are the structural analysis and the sectional analysis. Structural analysis involves modeling the structure as an assemblage of simpler elements and determining how the different elements contribute to resisting the applied loads.

Reinforced concrete (RC) short columns subjected to combined axial compression and biaxial bending are frequently encountered in RC structures such as buildings and bridges. Generally, the determination of the ultimate strength for RC columns of generic cross sections under eccentric compressive loading is rather tedious and time consuming. Various design aides have been developed mainly for rectangular and circular columns. Occasionally, the architectural considerations also require columns of nonconventional cross sections such as hollow sections and polygons. Therefore, additional analysis capabilities should be available to evaluate various design options conveniently.

The engineering staff of a producer of industrial gases used to have to spend long hours designing foundations for gas storage tanks. Each foundation involved a tedious series of hand calculations following a prescribed format that took about 40 hr. Now the process has been automated. TK Solver, a numerical problem solving software from Universal Technical Systems, Rockford, Illinois, was used to write out the entire sequence of equations involved in the design process. Then an application was written to prompt the user for all needed input and to duplicate the calculations exactly as they formerly would have been done by hand. The program reduced the time required to design each foundation from 40 hr to about 20 min. The equations, presentation view, and macro took about 160 hr to write. This included learning the program.

Through the years, the height of television towers has steadily increased. The Toronto Tower at 549 m (1782 ft) and the Moscow Tower at 537 m (1762 ft) are two of the tallest such towers in the world, and each was constructed of prestressed concrete. In China, several towers have surpassed the 300 m (1000 ft) plateau. Examples include towers in Tianjin, Beijing, and Nanjing, with heights of 415, 405, and 310 m (1362, 1329, and 1020 ft), respectively. In Shanghai, a 460 m (1510 ft) tower was successfully erected in 1994.

In the last 20 years, litigation involving structural engineers has increased dramatically. This is evidenced by the high cost of professional liability insurance. Often design professionals have been included in lawsuits in which they had no direct connection to the incident in question, other than being on-site during or near the time when the incident occurred. Consequently, some structural engineers have elected to visit job sites with decreasing frequency to reduce their exposure. This approach has not worked, and most structural engineers and insurers now realize that an increased job site presence is the best way to prevent errors that result in lawsuits. In part due to this realization, some national building codes have revised their provisions to require more stringent levels of inspection. These provisions are typically referred to as special inspections.

Distress to prestressed concrete railway ties placed somewhere on the eastern coast of the United States began to occur just a few years after installation. To determine the cause for the distress, a team representing various disciplines was assembled.

The first official record of an earthquake on the Japanese island can be found in the "Chronicles of Japan," ("Nihon Shoki") in the fifth year (416) of the reign of Emperor Ingyo. However, the scientific study of earthquakes was not started until the 1880 founding of the Japan Seismological Society following the Yokohama earthquake (M=5.5) which interested three engineering professors fro Europe: John Milne (1850-1913), James A. Ewing (1855-1935), and Thomas Gray (1850-1908).

OK, you've heard about the Information Superhighway, see the hype about getting on line with Prodigy, America Online and Compuserve and now you want to "surf the 'Net." Terrific!! Off to the local computer store you go, buy a modem and some software, spend a couple of days on the phone with various technical support departments, and you finally get the message that says you are on line: "CONNECT 14400." So where do you go from there? Where is all the neat stuff that is supposed to be on the Information Superhighway? There's a signpost up ahead, but in the back of your mind you hear Rod Serling saying that you have entered The Twilight Zone.

Concrete structural design is relatively simple if all materials are assumed to be linear elastic. In this case, the transformed-section method can be used. However, this linear elastic assumption is not always accepted. For example, ACI 318-89 clause 10.2.7 describes a rectangular stress block for concrete, and clause 18.3.2 describes concrete that is linear elastic, but cracked.