A diagram showing AE, VE, and Coastal A flood zones, each of which have different building requirements.

Summary of the codes and standards that regulate flood-proof construction.

An example of a temporary floodproofing technique used to protect this building from shallow flooding.

Foundation collapse due to flooding.

Flood Proof Construction

Through a grant from the Department of Homeland Security and the Southeast Region Research Initiative (SERRI), the GCCDS has begun a long-term research project focusing on Flood-Proof Commercial Construction and Fortified Residential Construction for Neighborhood-Scale, Mixed-Use Buildings.
The purpose of the project is to research the technical and regulatory factors of flood-proof construction for commercial building below the base-flood elevation combined with hurricane resilient construction for commercial or residential building above, and to design, build and test full-scale wall assemblies, in order to explore the performance, feasibility and cost of various wall assemblies. The research outcome will be used to demonstrate and educate architects, developers and municipal building officials.

Homeland security critical infrastructure protection is addressed by helping build commercial buildings that are resilient and able to be used soon after a hurricane in order to meet community needs and support local economic recovery.

Project Description
Task 1 Understand the hazards
Strong, flood-proof construction requires a clear understanding of structural design loads, water-tight performance, and long-term mold resistance. The structural loads include hurricane wind loads, impact loads, and the hydro-static and hydro-dynamic flood water loads. These loads will be modeled with computer structural analysis. The water-tight performance will be tested directly with mock-up assemblies. The short term and long term mold resistance can be predicted with an understanding of the dynamics of the building envelope and can be field tested along with the water-tight construction tests by monitoring the moisture and temperature of the mockup assembly.
The structural loads will be determined for the building’s structural system, for the building envelope, and for the windows and doors. Fortified construction is a rating that allows the building owner to receive a discount on their insurance rate. The wind load requirement for fortified construction is 20 miles per hour above the code requirement. The International Building Code specifies a 140 mile wind speed for Biloxi. Thus, the design wind speed for the building will be 160 miles per hour. The design pressure will be calculated from the required wind speed. The hydro-static and hydro-dynamic loads will be calculated by the structural engineer. The combined loading will be computer modeled.
FEMA has published recommendations and requirements for flood-proof construction. These publications are helpful, however, the final regulator of building construction is the local building official. Before the building is designed the flood-proof requirements will be discussed with the city’s building official to gain a preliminary approval of the proposed building.

Task 2 Investigate materials and assemblies.
Materials for flood-proof construction have demanding performance criteria. The materials must be strong and water-tight. The materials of construction should create a building that makes a good neighborhood and reinforces the enduring public value of architecture. In addition, the materials need to be affordable in order to make a mixed-use project feasible. A full-scale mock-up assembly will be constructed with the proposed building materials and assembly. The mock-up will be water tested to observe the performance of the assembly. Modifications will be made as necessary and the mock-up retested until a water-tight assembly is made.
The wall section drawing is the tool used by architects to work out the materials and assembly of a building. Many decisions are made that take into account the performance, the construction, the cost, and the aesthetics of the building. Research of materials is a necessary part of working out the wall section.
The wall section drawing will be used along with other necessary drawings and specifications to produce construction documents for the mock-up. The mock-up will be built by a qualified contractor, presumably the contractor that will build the complete building. It is important to use a contractor to build the mock-up to take advantage of the building knowledge as a way to refine and improve the architectural drawings. The mock-up has three goals. First, to construct a test wall. Second, to improve the design. Third, to help the contractor understand the construction that will be used in the complete building.
The mock-up wall panel will be tested for three performance requirements. First, the panel will be installed as one side of a tank that will be filled with water to check the hydrostatic strength and water-tightness of the assembly. Second the wall will be subjected to water sprayed under pressure to simulate the hydro-dynamic force of a storm surge. Third, moisture measuring instruments will be installed on the inside face and outside face of the wall for several days after flood testing to determine whether any moisture has gotten into the wall.
If mock-up wall does not perform as required the mock-up will either be modified or a completely new mock-up will be constructed. The modified or new mock-up will be retested. The process will continue until a mock-up is made that successfully meets the performance criteria.
The results of the mock-up and testing will be documented and complied into a summary report.

Task 3 Plan neighborhood land use.
The GCCDS has created a detailed GIS data base for all of the property in East Biloxi. The data base has been used for mapping and planning. It will be utilized in this project to make strategic land-use decisions, showing where commercial projects are best located considering the various ground elevations and the other urban design factors.
There are three historic commercial streets in East Biloxi: Main Street, Division Street, and Oak Street. A map will be produced showing the flood elevations as they vary along the three streets.
The flood information will be layered with other relevant property information to produce a strategic commercial district plan for each of the three streets. The plan will categorize the proposed land use into three groups: sites where commercial construction is possible without flood-proofing, sites where commercial construction requires flood proofing, and sites where commercial construction is not the best land use.

Task 4 Design a mixed-use building.
A mixed-use building will be designed in cooperation with the Biloxi Housing Authority. The ground floor will be used for retail and office space and the upper two floors will be rental housing. The building is expected to be around 10,000 sf on three floors.

Task 5 Inform the development community.
Designing a building with new performance criteria is a research activity that compares various alternatives and seeks to find the optimal solution. In the design process information is compiled and knowledge is acquired that can be documented for other projects. The completed project is a product of the intelligence gained from the design process and is the best demonstration for general issues that can be transferred to other similar projects. The GCCDS will document the design parameters, the solutions to the various performance criteria, the results of the mock-up testing, along with the final design. This documentation will be useful for other developers and for the general community to better understand flood-proof commercial construction.