Not quite equal to Dubai or Shanghai, but nevertheless the skyline of Puerto Vallarta is dotted with tower cranes evidencing the explosive growth and progress along the Mexican Riviera. These huge tower cranes are the modern form of balance cranes; not exactly what one would expect to see in a sleepy little Mexican fishing village. Of course, Vallarta is no longer sleepy or little with a population of 350,000 residents and growing daily.
During the past few years, large shopping centers, malls, and huge modern stores including Walmart, Sam´s Club, Costco, Home Depot, Office Supply, Liverpool, Soriana, Mega Mart, etc. have moved into the greater Vallarta area. The Maritime Terminal has tripled in size, the International Airport has quadrupled in size, the new University of Guadalajara branch has been constructed, the new public Auditorium and Conference Center has been built, three new large public parking lots have been constructed, and the general infrastructure is continuously expanding.
As for the tower cranes; they give the best combination of height and lifting capacity and are therefore used in the construction of tall buildings such as condominiums. There are currently approximately 7,000 condo units within the greater Vallarta area under various stages of construction everywhere from the planning phase to near completion. These do not include the additional 20,000 condominiums in Fonatur´s 15 year plan for the Nayarit Riviera, just north of Vallarta. The 7,000 condo units currently under construction are located in over 100 condo complexes; many being high rise buildings up to 24 stories tall, thus requiring the tower cranes.
Now, for the really interesting note; very few of the visitors to the area or even the residents living in Vallarta have noticed that these high rise buildings are being designed and constructed in three uniquely different fashions.
The majority of the buildings are of the conventional construction as used in Mexico for years. They consist of rebar reinforced concrete, whereby large reinforcement steel bars are bundled together, around which wooden forms are fabricated. Concrete is then poured inside the forms and around the rebars, creating a steel bar reinforced cast concrete structure. Concrete alone has high compressive strength but very poor tensile strength, whereas steel has very high tensile strength. By reinforcing the concrete with steel bars, the resulting structure has high compressive properties as well as high tensile properties, thus allowing the movement of tall buildings during earthquakes and high winds without cracking and other significant damage.
A second group of high rise condo buildings in the area consists of steel I beam and column construction, using concrete only for the floors. These buildings appear to be faster to construct because they can be built up two, three, or more stories at a time. Also, once the pre-designed steel components are at the construction site, there are few other trucks (such as the continuous flow of cement mixers) arriving at the construction site. The general construction area seems cleaner because there is no need for the wooden forms, piles of rebars, and miscellaneous concrete related materials. Also, the required manpower for the steel fabricated buildings seems to be somewhat less than that associated with the rebar reinforced concrete buildings. They do require a substantial amount of welding and cutting, however mechanical fasteners are also used for most connections. Steel fabricated buildings possess great compressive as well as tensile strengths; however the selection of this type of construction is most strongly influenced by the cost of steel relative to that of concrete.
The third group of high rise condo buildings in the Vallarta area is comprised of those of a hybrid construction. They consist of smaller steel beams encapsulated within reinforced cast concrete. The small I beams and columns are quite simple and fast to construct, after which they are surrounded by reinforcement steel bars. Next, as with the conventional reinforced concrete structures, wooden forms are constructed and concrete is poured around the steel columns and rebars. This combination of materials offers the advantages of both of the above methods of construction.
All three methods of construction require sophisticated engineering and design to assure long life and stability of the buildings during the most extreme weather conditions and earthquakes. Also, all of these large condominium buildings require substantial footings, drilling below ground as much as 100 feet to hit bedrock. Because all building designs are closely reviewed and must be approved by professional architects and engineers in the area prior to receiving building permits, it is safe to assume that all of the new structures are sound and will stand the test of time.
Regardless of the construction method, if the buildings are greater than about five stories tall, you can count on at least one tower crane to do the heavy lifting. These telescoping cranes are so versatile that a single operator located on the ground or near the work site can remotely manipulate the horizontal boom or jib, the trolley, and the cable motor that raises and lowers the load. Upon completion of the project, these large cranes come down piece by piece and are easily trucked off to another construction site.
Construction progresses rapidly in Vallarta because the climate is ideal for building year round. With average daily temperatures of 73°F and virtually no chance of rain from November through May, the work schedule is generally at least 10 hours per day, six days per week. During the rainy season of June through October, the rains generally occur between 4:00PM and 8:00PM, often reducing the work schedule to 8 hours per day, 6 days per week.
Now that we have a better understanding of what is being built in the area, those of us that live here ought to pay more attention to the new buildings and take notice as to what type of construction is being applied. For those of you that are considering a trip to Paradise, you will have something new to look at while sightseeing around the area; the crane invasion and the magnificent condominiums they are building!
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