Torrance Municipal Code Art. 3 Mandatory Seismic Strengthening Provisions for Non-Ductile Concrete Structures

815.3.010 PURPOSE.

The provisions of this Chapter are intended to promote the public welfare and safety by reducing the risk of death or injury that may result from the effects of earthquakes on older existing concrete buildings. In past earthquakes many of these types of structures have performed poorly and collapsed causing loss of life, personal injury, and substantial property damage. The poor performance of older concrete buildings is well documented and typically attributed to the non-ductile detailing of structural elements that render the building incapable of sustaining gravity loads when the building is subjected to earthquake-induced lateral displacements.

This Chapter creates minimum standards intended to improve the performance of these buildings during earthquakes and reduce, but not necessarily prevent, the loss of life, injury, or damage to property. The requirement for compliance with these standards does not preclude the utilization, at the Building Owner’s option, of a more extensive strengthening method that might further prevent or limit loss of life, injury, or building damage.

815.3.020 SCOPE AND APPLICABILITY.

The provisions of this Chapter shall apply to any existing Concrete Building determined by the Building Official to have been built under building code standards enacted before the 1979 Uniform Building Code with local amendments adopted on April 28th, 1981.

EXCEPTIONS:

This Chapter shall not apply to the following structure types:

(1) Concrete shear wall structures with flexible diaphragms.

(2) Single story structures, unless the lateral system contains concrete moment frame elements.

(3) Wood structures over concrete podium unless the podium contains a Major Deficiency as specified in section 815.3.050.a.

(4) Buildings with a steel lateral resisting system encased in concrete.

Notwithstanding any provision of the Building Code, compliance with this Chapter shall not require existing electrical, plumbing, mechanical or fire-safety systems to be altered to comply with existing code unless they constitute a hazard to life or property as determined by Building Official.

815.3.030 DEFINITIONS.

Notwithstanding the applicable definitions, symbols and notations in the Building Code, the following definitions shall apply for the purposes of this Chapter:

a) Building Code is the current Building Code of the City of Torrance.

b) Captive Column Deficiency occurs when there are columns at a level with height/depth ratios less than 50% of the nominal height/depth ratio of the typical columns at the level.

c) Concrete Building is a building having concrete floors and/or roofs, either with or without beams, and a lateral resisting system composed of concrete walls and/or concrete frames with or without masonry infills, or any combination thereof. Lift-slab buildings shall be considered as part of the concrete buildings with or without a concrete lateral resisting system.

d) Owner or Building Owner is the individual(s), agent, firm, corporation, or entity having legal possession, equitable interest in the property, or rights to sanction evaluation or retrofit of a building.

e) Historical Building is any building designated, or currently in the process of being designated, as a "qualified historical building" as defined in Part 8, Title 24 of the California Code of Regulations.

f) Load Path Deficiency occurs when a structure does not contain a complete, well defined lateral load path, including structural elements and connections, that serves to transfer the inertial forces associated with the mass of all elements of the building to the foundation.

g) Masonry Infill is the unreinforced or reinforced masonry wall construction within a reinforced concrete frame.

h) Owner of Building Owner is the individual(s), agent, firm, corporation, or entity having legal possession, equitable interest in the property, or rights to sanction evaluation or Retrofit of a building.

i) Retrofit is an improvement of the lateral force resisting system by alteration of existing structural elements or addition of new structural elements.

j) Soft Story Deficiency occurs when the stiffness of the seismic-force-resisting system in any Story is less than 70% of the seismic-force-resisting system in an adjacent Story above or less than 80% of the average seismic-force system stiffness of the three stories above.

k) Story is as defined in the Building Code, but includes any basement or underfloor space of a building with cripple walls exceeding four feet in height.

l) Story Strength is the total strength of all seismic-resisting elements sharing the same story shear in the direction under consideration.

m) Torsion Deficiency occurs when the estimated distance between the Story center of mass and the Story center of rigidity is more than 20% of the building width in either plan dimension.

n) Vertical Irregularity Deficiency exists when one or more vertical elements in the seismic-force-resisting system are not continuous to the foundation.

o) Weak Story Deficiency occurs when the sum of the shear strengths of the seismic-force-resisting system in any Story in each direction is less than 80% of the strength in the adjacent Story above.

815.3.040 COMPLIANCE REQUIREMENTS.

The Owner of each building within the scope of this Chapter shall cause an investigation of the existing construction and a structural analysis to be performed on the building by a Licensed Design Professional in the State of California. If the building does not meet the minimum standards specified in this Chapter, the Owner shall cause it to be structurally altered to conform to such standards.

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

Notwithstanding any other provisions of this Code to the contrary, a building that is found to be within the scope of this Chapter and is not brought into compliance in the time frame indicated in Table A, may be declared unsafe and subject to the requirements of Section 116 of the Building Code.

815.3.050 TIME PERIOD FOR COMPLIANCE/PRIORITY DESIGNATION.

a) Retrofit Phases. The Owner of any building subject to the provisions of this Chapter shall meet the requirements as specified in the following two Phases:

Phase 1: Engineering Report and Major Deficiency Mitigation. The Owner shall submit an engineering report to the Building Official demonstrating whether the structure conforms to the design provisions contained in this Chapter and identify all structural deficiencies in accordance with ASCE 41. Minimum report requirements shall be as specified by the Building Official. Buildings identified to have any of the Major Deficiencies listed below shall be required to Retrofit the building in such a way to mitigate the identified Major Deficiency within the time limits allowed in Table A. Alternatively, the engineering report may show that the Major Deficiencies meet the requirements of ASCE 41 through advanced analysis.

Major Deficiencies:

1. Load Path

2. Weak or Soft Story

3. Vertical Irregularity

4. Torsion

5. Captive Column

Alterations made to the structure to mitigate the Major Deficiencies listed above shall not impact existing lateral load elements by increasing any demand-to-capacity ratio by more than 10 percent unless the existing elements are shown to be capable of resisting the increased demand. In addition, the mitigation of the Major Deficiencies shall not create additional deficiencies or make the existing deficiencies more severe.

Phase 2: Complete Retrofit. The Owner shall complete the Retrofit of the structure to meet the requirements specified in Section 815.3.090 and mitigate all remaining deficiencies within the time limits allowed in Table A.

TABLE A TIME PERIOD FOR COMPLIANCE

1. All buildings within the scope of this Chapter are required to submit an engineering report and determine all structural deficiencies. Buildings that do not contain any of the Major Deficiencies as defined in this Chapter are not required to submit Retrofit plans for Major Deficiency mitigation, commence construction, and complete construction in Phase 1, but shall provide Retrofit plans and complete construction within the time limits provided in Phase 2.

2. Phase 1 Retrofit plans must indicate preliminary Phase 2 Retrofit extents. Minimum Phase 2 scoping requirements shall be as specified by the Building Official.

3. Completion of Phase 1 may be extended by 3 years if retrofit plans in accordance with the scope of Phase 2 are designed, approved, permitted, and constructed within Phase 1.

4. The Building Code version governing Phase 1 shall be permitted to be utilized in Phase 2.

b) Priority Designations. The Department shall prioritize its enforcement of this Chapter as defined in Table B.

TABLE B PRIORITY DESIGNATION

815.3.060 ADMINISTRATION.

a) Issuance of Order. The Building Official shall, in accordance with the priorities set forth in Table B, issue an order as provided in this Section to the Owner of each building that is expected to be within the scope of this Chapter.

b) Contents of Order. The order shall be in writing and shall be served by certified or registered mail to the Owner as shown on the last equalized Los Angeles County assessment roll of the building. The order shall specify that the building has been determined by the Building Official to be within the scope of this Chapter and, therefore, is required to meet the standards of this Chapter.

c) Service of Order. Proper service of a notice shall be by registered or certified mail. It shall be deemed a reasonable effort has been made to serve such notice when registered or certified letters have been mailed to the address of the interested party as shown on the official record. The designated period within which the Owner or person in charge is required to comply with such notice shall begin as of the date the Owner or person in charge receives such notice by personal service or certified mail.

d) Failure to Receive Order. Failure of any Owner, party concerned or other person to receive such notice shall not affect the validity of any proceedings taken thereunder.

e) Appeal from Order. The owner of any building may appeal any decision or order issued by the Building Official or his designee pursuant to this Chapter, including, but not limited to, the initial determination that a building is within the scope of the City of Torrance Seismic Retrofit Laws or the conclusion that a building must be retrofitted, to the City Manager or their designee. Any such appeal shall be filed with the City Manager within 30 days of the date of the Building Official’s or their designee’s order or decision. Any such appeal shall be decided by the City Manager no later than ninety days after filing. The filing of an appeal would stay the underlying order or decision and the associated time limits. Should the appeal be denied by the City Manager or their designee, the initial time limits shall be restored, unless the City Manager or their designee, authorizes alternate time limits. The City Manager’s or their designee’s decision shall be final except for judicial review.

f) Extensions. The Building owner may request an extension to the time period for compliance set forth in Table A of section 815.3.050. An application for extension may only be filed after the Owner has submitted an Engineering Report to the City with a determination of all deficiencies and the Retrofit Plans for major deficiency mitigation have been approved by the City. The Building Owner has the burden of proof to establish with substantial evidence that good cause for the extension exists. The Building Owner must also provide a new proposed schedule for compliance, and plan to comply with the provisions of this chapter during that timeframe. Upon good cause shown, the Building Official may approve, approve with modifications, or deny a request for an extension, commensurate with the justification for the extension.

g) Recordation. Once a building that was determined to be within the scope of this Article has failed to comply with the requirements of this Chapter within the time limits provided in Table A, the Building Official shall record in the office of the Los Angeles County recorder a certificate stating that the subject building is within the scope of this Article and requires seismic retrofit. The Certificate shall also state that the Owner thereof has been notified of the need to retrofit the building. Once the building has been retrofitted to comply with this Chapter, the Building Official shall record a Certificate indicating that the subject building no longer is in violation of this Chapter.

h) The Building Official may promulgate implementing regulations and policies consistent with this Chapter.

815.3.070 OCCUPANCY AND TENANT ADVISORY.

Notification to Tenants and Occupants. The Owner shall notify in writing all current and prospective residential and non-residential tenants, subtenants, lessees, sublessees, or any other person(s) entitled to the use and/or occupancy of the building of a proposed project submitted pursuant to this Chapter. The notice shall include the information for the project, as determined by the City, including the scope of work, expected duration, and contact information for a representative of the contractor. The form of notice shall be supplied by the Community Development Department and Building Safety Division.

815.3.080 HISTORICAL BUILDINGS.

Historical Buildings shall comply with the California Historical Building Code and the provisions of this Chapter. Modifications to the standards set forth in this Chapter may be permitted when such modifications are consistent with the provision of the California Historical Building Code. Such modifications shall be clearly specified in the engineering report and Retrofit drawings.

815.3.090 ENGINEERING ANALYSIS AND DESIGN.

a) Scope of Analysis. This Chapter requires the evaluation, alteration, repair, replacement or addition of structural elements and their connections to meet the requirements of this section.

b) Building Structural Analysis, Design and Evaluation. The building shall meet or exceed the structural performance level for the associate earthquake hazard levels as indicated in Table C based on the Risk Category as defined in ASCE 41:

Table C Seismic Performance Requirements by Risk Category

c) Material Testing and Condition Assessment. The engineer shall conduct material testing and condition assessment on the existing structure as specified by the Building Official.

d) Alternate Analysis, Base Shear and Design Parameters. The Building Official may approve alternate design methodologies that meet the same performance intent as those prescribed by the Chapter and that achieve the objectives established by the Chapter. Design criteria shall be submitted to the Building Official for review and approval prior to submission of plans.

815.3.100 INFORMATION REQUIRED ON PLANS.

a) General. In addition to administrative items, the plans and specifications required by the Building Official shall be of sufficient clarity to indicate the nature, design methodology, and extent of the proposed work and to show in detail that it will conform to the provisions of this Chapter and the Building Code.

b) Phase 1 Licensed Design Professional Statement. Where engineering plans are required, the responsible Licensed Design Professional shall provide the following statements on the approved plans:

I am responsible for designing this building’s Phase 1 seismic strengthening in compliance with the minimum standards of the Mandatory Seismic Strengthening Provisions for non-Ductile Concrete structures (Division 8, Chapter 15, Article 3 of the Torrance Municipal Code).

c) Phase 2 Licensed Design Professional Statement. The responsible Licensed Design Professional shall provide the following statements on the approved plans:

I am responsible for dsigning this building’s Phase 2 seismic strengthening in compliance with the minimum standards of the Mandatory Seismic Strengthening Provisions for non-Ductile Concrete structures (Division 8, Chapter 15, Article 3 of the Torrance Municipal Code).

d) Phase 1 Owner or Owner’s Representative Statement. Unless the entire building has been retrofitted to meet the full intent of the current building code, the Owner shall provide and sign the following statement on the cover of the drawings:

I _______ understand the seismic evaluation and strengthening performed under this project is limited to a Deficiency only Mitigation under the Phase 1 requirements of the Mandatory Seismic Strengthening Provisions for non-Ductile Concrete structures (Division 8, Chapter 15, Article 3 of the Torrance Municipal Code) which is intended to limit the risk under a seismic event. I understand the full building has not been strengthened for other potential structural deficiencies that may cause a life safety concern, injury, or property damage risk under a seismic event.

e) Phase 2 Owner or Owner’s Representative Statement. The Owner shall provide and sign the following statement on the cover of the drawings:

I _______ understand the seismic evaluation and strengthening performed under this project is in conformance with the Mandatory Seismic Strengthening Provisions for non-Ductile Concrete structures (Division 8, Chapter 15, Article 3 of the Torrance Municipal Code) which is intended to limit the risk under a seismic event.

f) Quality Control and Assurance Requirements. General notes shall show the requirements for material testing, special inspection, structural observation, and the proper installation of newly added materials.

815.3.110 QUALITY ASSURANCE.

a) Structural Observation. All structures regulated by this Chapter require structural observation during construction. The Owner shall employ the Engineer of Record responsible for the structural design, or another registered Engineer designated by the Engineer of Record to perform structural observation as defined in the Building Code.

b) Special Inspection. Special inspections shall be provided as required by the Building Code. Additional inspections shall be noted on drawings as required by Building Official.

815.3.120 VIOLATION/PENALTY.

a) Violation. Notwithstanding any other provisions of this Code to the contrary, it shall be unlawful for any person, firm or corporation, to own, use, occupy or maintain any building or structure or portion thereof, in the unincorporated portion of the County, or cause the same to be done, contrary to, or in violation of, any of the provisions of this Code.

b) Penalty:

(1) Any person who violates any provision of this Article is guilty of a misdemeanor unless the violation is cited or charged by the City or the City Attorney and/or reduced to an infraction.

(2) Each such person charged with a misdemeanor shall be guilty of a separate offense for each and every day or portion thereof during which any violation of any of the provisions of this code is committed, continued or permitted, and upon conviction of any such violation such person shall be punishable by a fine of not more than $1,000 (one thousand dollars), or by imprisonment for not more than six months, or by both such fine and imprisonment. The provisions of this section are in addition to and independent of any other sanctions, penalties, or costs which are or may be imposed for a violation of any of the provisions of this code;

(3) Any violations of this Article may result in civil, criminal and/or administrative enforcement actions.

c) Recordation of violation.

(1) General. The Building Official may record a notice with the County Recorder’s Office that a property, building or structure, or any part thereof, is in violation of any provision of this Code provided that the provisions of this section are complied with. The remedy provided by this section is cumulative to any other enforcement actions permitted by this Code.

(2) Recordation. If (A) the Building Official determines that any property, building, or structure, or any part thereof is in violation of any provision of this Code; and if (B) the Building Official gives written notice as specified below of said violation; then the Building Official may have sole discretion to, at any time thereafter, record with the County Recorder’s Office a notice that the property and/or any building or structure located thereon is in violation of this Code.

(3) Notice. The written notice given pursuant to this Section shall indicate:

a) The nature of the violation(s); and

b) That if the violation is not remedied to the satisfaction of the Building Official, the Building Official may, at any time thereafter, record with the County Recorder’s Office a notice that the property and/or any building or structure located thereon is in violation of this Code. The notice shall be posted on the property and shall be mailed to the owner of the property as indicated on the last equalized County Assessment roll. The mailed notice may be by registered, certified, or first-class mail.

(4) Rescission. Any person who desires to have recorded a notice rescinding the notice of violation must first obtain the necessary approvals and permit(s) to correct the violation. Once the Building Official determines that the work covered by such permit(s) has been satisfactorily completed, the Building Official may record a notice rescinding the prior notice of violation.

Following the recordation of the notice of violation the Building Official is not required to make any inspection or review of the premises to determine the continued existence of the cited violation. It is the responsibility of the property owner, occupant or other similarly interested private party to comply with the above provisions.

d) Costs. Any person that has violated any provision of this Code shall be responsible for the costs of any and all Code Enforcement actions taken by the Building Official in response to such violations. These costs shall be based on the amounts specified by the current fee schedule.

815.3.130 APPLICABILITY.

a) Internal conflict. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall be applicable. Where, in any specific case, different Sections of this Code specify different materials, methods of construction, or other requirements, the most restrictive shall govern.

b) Other laws. The provisions of this code shall not be deemed to nullify any provisions of local, state, or federal law.

c) Codes and references. The provisions of the codes and standards referenced in this Code shall be considered part of the requirements of this Code to the prescribed extent of each such reference. Where there are conflicts between the provisions of this Code and the provisions of any referenced code or standard, the provisions of this Code shall apply.