1. Field of the Invention
The present invention relates to a method of erecting a building or like structure wherein a pre-cast concrete chain wall is first constructed and then transported to a selected building site. Even more particularly, the present invention relates to an improved method of elevating a building or other structure or equipment at a lower cost and/or reduced construction time.
2. General Background of the Invention
Cast-in-place concrete chain walls are typically used to elevate buildings in flood prone areas. One of the most common usages of the chain walls are for prefabricated modular buildings used by telecommunications or other communication companies.
Each individual company normally uses a standard size building. Thus the footprint of the chain wall is normally constant. The time and construction cost for building a cast-in-place chain wall at a particular site can be extremely expensive and time consuming.
After the concrete is poured, the concrete must be allowed time to cure. The wooden forms used for cast-in-place chain walls are then removed and typically disposed of. This entire process could range from 2-4 weeks (even longer if there are delays in obtaining materials or due to weather). There are known cases in which the wooden forms have failed and the final walls are bowed out of alignment. The concrete must be delivered to the site from a concrete plant which could be several miles from the site location. The compressive strength of the cast-in-place concrete chain wall is usually determined 28 days after the concrete is poured.
The present invention provides an improved method of installing an elevated building at a particular location and in a shorter time frame. The present cast-in-place method usually requires a contractor to order wooden forms, steel reinforcing bars, concrete trucks to pour, labor to form and pour the cast-in-place chain wall, and possible pump trucks and matting.
The present invention has many advantages over the current cast-in-place type systems. The pre-cast chain wall can be poured and stored in a storage facility months prior to the beginning of a job. The forms used for the pre-cast chain wall system can be metal, which can be used many times. The concrete can be poured in ideal weather conditions and is usually supplied by an on-site concrete manufacturer. The metal forms can be specifically tooled to accept attachments for landing, tie-down plates or other attachments which are typically required by the client.
These metal forms can be built with vertical grooves or any other type of decorative pattern to make the finished product more aesthetically pleasing than the present cast-in-place chain wall.
The exterior walls for the pre-cast chain wall can be smoother and contain little to no honeycomb finishes as compared to the cast-in-place chain wall. The steel reinforcement could be ordered in large quantities and shipped to the fabrication plant. The cast-in-place concrete chain walls can be poured in one day, and then set aside for curing. The fabrication plant can stockpile these pre-cast chain walls and deliver them as needed.
When a client orders a pre-cast concrete chain wall, he will know the compression strength of his new concrete wall before it is delivered to his site. The construction time for placing a pre-cast chain wall on site can be reduced from 2-4 weeks to a week or even a day.
As with a standard cast-in-place chain wall, a foundation is needed in some cases to support the wall and building. If for example, pilings are required to support the wall and building, the pilings could be driven to a certain elevation, and then the pre-cast chain wall can be placed on top of the piles, followed by the new prefabricated modular building.
A crane large enough to place the prefabricated modular building can first be used to set the lighter pre-cast concrete chain wall in place on top of the piles. The modular building can be attached to the chain wall using tie-down plates with bolts. The pre-cast chain walls can be made such that the tie-down bolts can double as attachments for lifting the wall.
A typical size (approximate dimensions) of a chain wall is 11 feet 6 inches×20 feet×4 feet high with wall thickness of 10 inches. These dimensions will vary based on the client's need and the building or structure loads.