Arcadia Municipal Code Part 2 Tilt-Up Concrete Wall Buildings

The purpose of this Part is to promote public safety and welfare by reducing the risk of death or injury that may result from the effects of earthquakes on tilt-up concrete wall buildings designed under the building codes in effect prior to January 1, 1976. Such buildings have been categorized based on past earthquakes, as being potentially hazardous and prone to significant damage, including possible collapse, in a moderate to major earthquake.

The provisions of this Part are minimum standards for structural seismic resistance established primarily to reduce the risk of loss of life or injury on both subject and adjacent properties and will not necessarily prevent loss of life or injury or prevent earthquake damage to an existing building which complies with these standards. The requirement for compliance with these standards does not preclude the utilization, at the building owner's option, of more extensive strengthening method that might further prevent or limit loss of life or injury or building damage. This Part shall not require existing electrical, plumbing, mechanical or fire safety systems to be altered unless they constitute a hazard to life or property.

This Part provides systematic procedures and standards for identification and classification of tilt-up concrete wall buildings based on the current use of the buildings. Priorities, time periods and standards are also established under which these buildings are required to be structurally analyzed and strengthened for seismic resistance. Where the analysis determines structural deficiencies, this Part requires the buildings to be strengthened or demolished.

The provisions of this Part shall apply to all buildings designed or built under building codes in effect prior to January 1, 1976, which, on the effective date of this Part have tilt-up concrete walls as defined in this Part.

Buildings within the scope of this Part may not be added to or structurally altered or remodeled without first complying with the provisions of this Part unless the Building Official determines that the alteration is minor in nature.

Seismic strengthening in place prior to the effective date of this Part shall be evaluated according to the provisions of this Part and modified to comply if deficient.

For purposes of this Section, the applicable definitions in Sections 2302, 2331, 2502 and 2602 of the 1991 Edition of the Uniform Building Code (UBC) shall also apply.

Board shall refer to the Arcadia Building Code Appeals Board.

Construction pursuant to a valid building permit has progressed to the point that one of the called inspections as required by the department has been made and the work for which the inspection has been called has been judged by the department to be substantial and has been approved by the department.

For the purposes of this Part, any building housing a hospital or other medical facility having surgery or emergency treatment areas, fire or police stations, municipal government disaster operations and communication centers.

A form of precast concrete panel construction either cast in the horizontal position at the site and after curing, lifted and moved into place in a vertical position, or cast off-site in a fabricator's shop.

The Uniform Building Code shall be referred to as the UBC.

The rating classifications as exhibited in Table No. 89-H are established and each building within the scope of this Part shall be placed in one such rating classification by the department. The total occupant load as determined by UBC Section 3302(a) of this Code for the entire building plus the occupant load of any adjacent building which interconnects with the subject building or uses the subject building for exiting purposes shall be used to determine the rating classification.

The owner of each building within the scope of this Part shall cause an investigation of the existing construction and a structural analysis to be made of the building by a civil or structural engineer or architect licensed by the State of California, and if the building does not meet the minimum standards specified in this Part, the owner shall cause it to be structurally altered to conform to such standards or cause the building to be demolished.

The owner of the building within the scope of this Part shall comply with the requirements set forth in this Part by submitting to the department for review within two hundred seventy-five (275) days after the service of the order the following:

(a) A structural analysis, subject to approval by the department within the two hundred seventy-five (275) day time period, which demonstrates that the building meets the minimum requirements of this Part; or

(b) A structural analysis and plans for the proposed structural alterations of the building necessary to comply with the minimum requirements of this Part; or

(c) Plans for the demolition of the building.

After plans are submitted and approved by the department, the owner shall obtain a building permit, commence and complete the required construction or demolition within the time limits set forth in Table 89-I. These time limits shall begin to run from the date the order is served in accordance with Section 8925.1 and 8925.2 of this Part. Vacating a building shall not be deemed as complying with the requirements of this Part.

8925.1. Service of Order. When the department determines that a building is within the scope of this Part, the owner shall comply with Section 8924 of this Code. If the owner does not comply, the department shall issue an order as provided in Section 8925.2 to the owner of each building with the minimum time periods for service of such orders set forth in Table No. 89-J. The minimum time period for the service of such orders shall be measured from the effective date of this Part.

8925.2. Contents of Order. The order shall be in writing and may be given either by personal delivery thereof to the owner or by deposit in the United States mail in a sealed envelope, postage prepaid, addressed to the owner as shown on the last equalized assessment roll. Service by mail shall be deemed to have been completed at the time of deposit in the post office. The failure of any owner to receive such notice shall not affect in any manner the validity of any of the proceedings taking thereunder. Proof of giving any notice may be made by an affidavit of any employee of the City which shows such service in conformity with this Section. Department administrative action, other correspondence between the City and the building owner or building owner's representative, or other evidence of knowledge of notification shall also be deemed as proof of giving notice.

The order shall specify that the building has been determined by the department to be within the scope of this Part, and therefore, is required to meet the minimum seismic standards of this Part. The order shall specify the rating classification of the building and shall be accompanied by a copy of Section 8924 which sets forth the owner's alternatives and time limits for compliance.

8925.3. Appeal from Order. The owner of the building may appeal the department's determination that the building is within the scope of this Part to the Arcadia Building Code Appeals Board. Such appeal shall be filed with the building official within thirty (30) days of the service date of the order described in Section 8925.2. Such appeal shall be made in writing setting forth clearly and concisely the reasons for appeal. Each appeal shall be accompanied by a filing fee as set forth by resolution of the City Council.

8925.4. Recordation. At the time that the department serves the aforementioned order, the department shall file with the office of the County Recorder a certificate stating that the subject building is within the scope of Part 2 - "Earthquake Hazard Reduction in Existing Tilt-up Concrete Wall Buildings" of this Code. The certificate shall also state that the owner thereof has been ordered to structurally analyze the building and to structurally alter or demolish it when the department determines the building is not in compliance with Part 2 of this Code.

If the building is either demolished, found not to be within the scope of this Part or is structurally capable of resisting minimum seismic forces required by this Part as a result of structural alterations or an analysis, the department shall file with the office of the County Recorder a Certificate terminating the status of the subject building as being classified within the scope of Part 2 "Earthquake Hazard Reduction in Existing Tilt-up Concrete Wall Buildings" of this Code.

8925.5. Enforcement. If the owner of the subject building fails to comply with any order issued by the department pursuant to this Part within any of the time limits set forth in Section 8924, or within any additional time limits as may have been granted by the Board, the department may order that the building be vacated and subsequently ordered to be demolished in accordance with the provisions of Section 8924 of this Code. The Building Official shall have the authority to grant two one (1) year extensions in cases of extreme hardship.

8926.1. Wall Panel Anchorage. Concrete walls shall be anchored to all floors and roofs which provide lateral support for the wall. The anchorage shall provide a positive direct connection between the wall and floor or roof construction capable of resisting a horizontal force equal to thirty percent (30%) of the tributary wall weight for all buildings and forty-five percent (45%) of the tributary wall weight for essential buildings, or a minimum force of two hundred (200) pounds per linear foot of wall, whichever is greater. The required anchorage shall be based on the tributary wall panel assuming simple supports between floor and roof or between floor and floor.

EXCEPTION. Alternative design may be approved by the Building Official when justified by well established principles of mechanics.

8926.2. Special Requirements for Anchors. Wall anchors shall be provided to resist out-of-plane forces, independent of existing shear anchors. The wall anchor systems shall be capable of developing yield in the body of the anchor or the system without inducing brittle failure to the concrete to which the anchors are attached.

EXCEPTION. Existing cast-in-place shear anchors may be used as wall anchors if the tie element can be readily attached to the anchors and if the engineer or architect can establish tension values for the existing anchors through the use of approved as-built plans or testing, and through analysis showing that the bolts are capable of resisting the total shear load while being acted upon by the maximum tension force due to earthquake. Criteria for analysis and testing shall be determined by the Building Official.

Expansion anchors are not allowed without special approval of the Building Official. Attaching the edge of plywood sheathing to steel ledgers is not considered as complying with the positive anchoring requirements of this Code, and attaching the edge of steel decks to steel edges is not considered as providing the positive anchorage of this Code unless testing and/or analysis are performed which establish shear values for the attachment perpendicular to the edge of the deck.

8926.3. Development of Anchor Loads into the Diaphragm. Development of anchor loads into roof and floor diaphragms shall comply with Section 2337(b)9.C. of the UBC.

In wood diaphragms, anchorage shall not be accomplished by use of toe nails or nails subject to withdraw, nor shall wood ledgers, top plates or framing be used in cross-grain bending or cross-grain tension. The continuous ties required by Section 2337(b)9.C. of the UBC shall be in addition to the diaphragm sheathing.

Lengths of development of anchor loads in wood diaphragms shall be based on existing field nailing of the sheathing unless existing edge nailing is positively identified on the original construction plans or at the site.

At reentrant corners, continuity collectors may be required for existing return walls not designed as shear walls, to develop into the diaphragm a force equal to the lesser of the rocking or shear capacity of the diaphragm. Shear anchors for the return wall shall be commensurate with the collector force. If a truss or beam other than rafters or purlins is supported by the return wall, an independent secondary column is required to support the roof or floor members whenever rocking or shear capacity of the return wall is governing.

8926.4. Girder Anchorage at Support. In addition to the anchorage required per Section 8926.1. girder to pilaster connections shall be verified for the tributary wall anchoring load per Section 8926.1 of this Code, considering the wall as a two-day slab. Adequacy of existing lateral confinement of vertical girder anchor at the top of the pilasters shall be verified per Section 2607(k)3.D. of the UBC. If the confinement is inadequate, additional exterior confinement shall be provided. A continuous load path from the pilaster, through the girder and to the diaphragm shall be verified.

EXCEPTION. The requirement for additional confinement and/or adequate strength of existing girder anchor bolts at the top of the pilaster may be waived if the girder is anchored directly to the walls immediately adjacent to the pilaster, or to the pilaster, for the total lateral force such that the existing girder anchor bolts are by-passed without causing shear failure at the top of the pilaster.

8926.5. Crack and Damage Repairs, Evaluation of Existing Structural Alterations.

The engineer shall report any observed structural conditions and structural damage that have imminent life safety effects on the buildings and recommend repairs. Evaluations and repairs shall be reviewed and approved by the department.

The engineer shall also evaluate the effects of alterations such as openings cut in existing wall panels without a permit, that may present immediate life safety hazard and correct when necessary.

8926.6. Miscellaneous. Existing mezzanines relying on the tilt-up walls for vertical and/or lateral support shall be anchored to the walls for the tributary mezzanine load. Walls depending on the mezzanine for lateral support shall be anchored per Section 8926.1, 8926.2 and 8926.3.

EXCEPTION. Existing mezzanines that have independent lateral and vertical support need not be anchored to the walls.

Existing interior masonry or concrete walls not designed as shear walls, that extend to the floor above or to the roof diaphragm shall also be anchored for out-of-plane forces per Section 8926.1, 8926.2 and 8926.3 of this Code. In the in-plane direction, the walls may be isolated or shall be developed into the diaphragm for a lateral force equal to the lesser of the rocking or shear capacity of the wall, or the tributary shear but not exceeding the diaphragm capacity.

All materials permitted by this Code, including their appropriate allowable stresses and those existing configurations of material specified in Part 1 of this Code, may be utilized to meet the requirements of this Part.

In addition to the seismic analysis required elsewhere in this Part, the licensed engineer or architect responsible for the seismic analysis of the building shall record the information required by this Section on the approved plans.

The plans shall accurately reflect the results of the engineering investigation and design and show all pertinent dimensions and sizes for plan review and construction. The following shall be provided:

(a) Floor plans and roof plans shall show existing framing construction, diaphragm construction, proposed wall anchors, cross-ties and collectors. Existing nailing, anchors, ties and collectors shall also be shown on the plans if these are part of the design, and these structural elements need to be verified in the field.

(b) At elevations where there are alterations or damage, details shall show roof and floor heights, dimensions of openings, location and extent of existing damage, and proposed repair.

(c) Typical wall panel sections with panel thickness, height, location of anchors shall be provided.

(d) Details shall include existing and new anchors and the method of development of anchor forces into the diaphragm framing; existing and/or new cross-ties; existing and/or new or improved support of roof and floor girders at pilasters or walls.

The responsible engineer or architect shall state on the approved plans, the following:

(a) I am responsible for this building's seismic strengthening design in compliance with the minimum seismic resistance standards of Part 2 of this Chapter.

(b) The Registered Deputy Inspector, required as a condition of the use of structural design stresses requiring continuous inspection, will be responsible to the Building Official as required by Section 306(a) of the UBC.

Every building within the scope of this Part which has been analyzed to demonstrate compliance or structurally altered to comply with the minimum earthquake standards in this Part shall be maintained in conformity with the requirements of this Part in effect at the time of such analysis or structural alteration.

Notwithstanding any other provisions of this Code to the contrary, it shall be unlawful for any person, firm or corporation to maintain, use or occupy any building within the scope of this Part which does not meet the minimum earthquake standards specified in this Part.

Any person who violates or causes or permits another person to violate this provision is guilty of a misdemeanor. Any person includes an owner, lessor, sublessor, manager or person in control of a building subject to this Part. This term shall not include any person who is merely a tenant or other individual occupying any dwelling unit, efficiency dwelling unit, guest room or suite in a building.

The legal owner of a building is that person, firm, corporation, partnership, or other entity whose name or title appears on the record with the Los Angeles County Recorder's office, as well as all successors or assignees of these persons.

EXCEPTION: This Section shall not apply if alteration or repair work has commenced in order to bring the building into compliance with the requirements of this Part, and such work is proceeding in accordance with the time limits set forth in order of the department or determination of the board.

Table No. 89-H Rating Classifications

Table No. 89-I Time Limits For Compliance

Table No. 89-J Service Priorities

(Part 2 added by Ord. 2033 adopted 2-7-95)