Toddler Center

Child Development Center is a former carriage house constructed in 1890. The structure was upgraded without impacting the character of the building. The Toddler Center provides day care for 77 toddlers and has school class room and offices on the second floor. The seismic retrofit upgrade includes structural steel frames, shotcrete and wood shear walls, roof and second floor diaphragms, and foundation strengthening. Through close collaboration between educators, architect, engineers and the community the local historic preservation group recognized and commended the effort to give new life to the carriage house while preserving the historic fabric of the surround campus and neighborhood.

Irving

The structure is a one-story classroom building with precast concrete tilt-up panels. Due to its saw-tooth profile, the retrofit design is more complex than that for a typical roof profile. The approved design calls for a complete strengthening of the roof system in light of poor performance with tilt-up construction during previous major seismic events. The retrofit design provides a lateral force system that incorporates structural steel braces in place of current steel rods at the large window openings. The retrofit also involves tying the paneled walls together to prevent against out-of-plane failure.

Ahmanson Commons

The Ahmanson Commons is historic building constructed in 1903 and is located on a private college campus. The building includes a cafeteria and kitchen on the first floor, as well as offices and dorms on the second and third. The structure has an unreinforced masonry basement. The first floor of the building was modernized that included removing walls in order to make a large dining area for students and staff. The structural retrofit greatly improved the seismic performance of this historic building. The retrofit included steel and wood frames, shear walls, and the strengthening of the unreinforced masonry foundation

New Tech High

EAS performed a structural analyses on the annex wing of the main building, specifically the 1927 and 1929 additions. The analyses were performed because New Tech High project specifies some structural alterations and other conversion work as shown on the preliminary plans. These two additions were constructed with unreinforced masonry (URM) and hollow clay tiles for the walls in conjunction with wood framing for the classroom floors and concrete slab for the corridors. The roof diaphragm is wood frame construction. A retrofit upgrade and repair plan was prepared for these two buildings in December 1934 and they were subsequently strengthened. Although they were constructed separately, the two buildings are linked to each other by means of a seismic joint. With this in mind, they are treated as individual buildings for the analyses. Each building had been considerably retrofitted perhaps due to damage caused by the Long Beach earthquake in the early 1930s. The scope of the retrofit was substantial, requiring a few URM walls to be entirely replaced by cast-in-place concrete walls. The retrofit plan also specified one layer of brick from the each URM wall be removed and gunited over from top to bottom. Other significant work included the replacement of the entire parapet with concrete, the addition of pilasters at strategic places along each URM wall, the addition of concrete diaphragm chords, and the enlargement of existing footings.

Niklor Chemical

EAS performed seismic analyses, strengthening and foundation design for an Evaporator Tower, Bleach Tanks and Waste Water Tanks. The Evaporator Tower was placed on drilled pier concrete foundations, the tanks were placed on concrete mat foundations.

Fitness Club - TI

This facility was upgraded to accommodate a membership fitness club on the second floor. The structure has a long span floor system to eliminate columns and provide large open spaces on the first and second floors. The floor and roof system is constructed of prestressed concrete planks. The retrofit strengthening includes improving connections and installing lightweight support beams in selected locations.

Parking Garage

EAS was issued a contract to provide a structural evaluation and retrofit for the a Civic Center Court House Parking Garage.The parking garage was constructed in 1976. It is three-stories and has a total of four levels of parking. The building is 35 feet in height and 330 feet by 305.5 feet in plan dimension. There is elevator access to each level along with four stair towers. The parking garage has one car ramp that spirals up and down through the interior of the garage. The criterion for the structural evaluation is the 2006 IBC, 2007 CBC (3415.5), ASCE 41, ASCE 31 and the Los Angeles County Building Code. The criterion used for evaluation of existing buildings provides a minimum level of seismic performance. A three dimensional finite element model of the building was prepared utilizing the ETABS computer software. The three dimensional analyses has the appropriate building mass and stiffness properties. Therefore, the analyses include torsion effects on the building. The model includes shell elements with both in and out-of-plane stiffness properties for walls and slabs. Beam elements are used for double tees, girders and columns. The floor openings are considered and the ramps are included in the model. The floor and roof slab is considered to be a stiff diaphragm. The model boundary support conditions provide a fixed base.

Granada Hills Medical Building

EAS provided a structural evaluation report of the Granada Hills Medical Building for adaptive reuse. The building was constructed in 1978. It is three-stories, 38.5 feet in height excluding the parapet and 94.67 feet by 92 feet in plan dimension. There are two elevators and two stair towers that access each level. The criterion for the structural evaluation is the 2006 IBC, 2007 CBC (3415.5), ASCE 41, ASCE 7 and ASCE 31. The criterion used for evaluation of existing buildings provides a minimum level of seismic performance. A three dimensional finite element model of the building was prepared utilizing the ETABS computer software. At this essential life-safety level, persons in the building will be able to exit or be evacuated from the building following an earthquake. It does not mean that persons will not be injured or not be in need of medical attention. This level of seismic performance is presumed achieved when the building has some margin against either total or partial collapse of the structural system even though significant damage may have occurred that may not be economical to repair. The Medical Office Building did comply with the ASCE 31 criteria as specified by Seismic Evaluation of Existing Buildings for life safety performance.

Saint Julian Warehouse

EAS provided a structural evaluation of an old old high-rise structures to determine its structural integrity. This warehouse is especially complex given its age, archaic construction materials, framing system and other variables. These types of projects require extensive knowledge and experience in earthquake engineering, computer modeling, analyses and design. The District warehouse is an 8-story building designed in 1926. Its structural system consisted of non-ductile concrete frames with unreinforced masonry and concrete in-fills. The entire structure was modeled using the ETABS software to simulate its behavior under a progressively increasing lateral seismic load to complete collapse, also known as a pushover analysis. The result of the analyses is a force-displacement curve that categorizes the building behavior as ductile, semi-ductile or brittle. Due to its complexity, the computer model was required to establish acceptance criteria as well as to determine the performance of the facility during an earthquake, and ultimately provide a set of structural plans for upgrading the structure.