It is found and declared that in the event of a strong or moderate local earthquake, loss of life or serious injury may result from damage to or collapse of buildings in Norco. It is generally acknowledged that Norco will experience earthquakes in the future due to its proximity to Seismic Zone 4. The purpose of this ordinance is to promote public safety by identifying those buildings in Norco which exhibit structural deficiencies and by accurately determining the severity and extent of those deficiencies in relation to their potential for causing loss of life or injury. The City Council finds it desirable to identify the hazards that these deficiencies may pose to occupants of buildings and pedestrians in the event of an earthquake. Such a seismic hazards identification program is consistent with California Health and Safety Code sections 19160–19169, SB 547.
(1) "Bearing wall"
means any wall supporting a floor or roof where the total superimposed load exceed one hundred (100) pounds per linear foot, or any unreinforced masonry wall supporting its own weight when over six (6) feet in height.
(2) "Building,"
for the purpose of determining occupant load, means any contiguous or interconnected structure; for purposes of engineering evaluation, means the entire structure or a portion thereof which will respond to seismic forces as a unit.
(3) "Capacity for transfer"
means the maximum allowable capacity of a structural system or connection to resist in a ductile manner the lateral forces it would encounter due to earthquake forces.
(4) "Civil engineer or structural engineer"
means a licensed civil or structural engineer registered by the State of California pursuant to the rules and regulation of Title 16, Chapter 5 of the California Administrative Code.
(5) "External hazard"a. b. c. d. e. f. g. h.
means an object attached to or forming the exterior facade of a building which may fall onto pedestrians or occupants of adjacent buildings. Examples of this type of hazard include, but are not limited to, the following:
Nonstructural exterior wall panels, such as masonry infill or decorative precast concrete.
Parapets.
Marquees, awnings or other roof-like projections from a building.
Masonry or stone wall veneer and wall ornamentation, including cornices or other decorative appendages.
Masonry chimneys.
Tile roofing.
Wall signs and exterior lighting fixtures hung from a building exterior.
Fire escapes or balconies.
(6) "Geometry"
means a building's shape or configuration, including setbacks or wall/column lines, reentrant corners, discontinuities in vertical and horizontal lateral force diaphragms, open storefront and building stiffness variations due to the distribution of resisting elements or the use of materials of differing properties within the same structural element, or other irregularities in plan or elevation.
(7) "Occupants"
means the total occupant load of a building determined by Table 33-A of the 1988 Uniform Building Code or the actual maximum number of occupants in that building if that number is less than seventy-five percent (75%) of the number determined by using Table 33-A. The number of actual occupants may be documented by counting actual seating capacity if permanent seating is provided in the occupancy, or by employee and client counts which can be substantiated as a practical maximum use of the space in the building. The chief building official will establish the procedure for documenting occupant loads.
(8) "Solution"
means any justifiable method that will provide for the transfer of lateral forces through a system or connection to a degree which will substantially eliminate a potential collapse failure. A general description of the methods and materials to be used shall be included in sufficient detail to allow for a cost estimate of the solution to be made (i.e., adding shear walls, over-laying horizontal diaphragms, strengthening critical connections, etc.).
(1)
Applicability. The following buildings in Norco shall be required to have an engineering report submitted to the City's Building and Safety Inspection Division, pursuant to Section 1.5, to determine:
(i)
the existence, nature and extent of structural deficiencies which could result in collapse or partial collapse of the building; and
(ii)
the existence, nature and extent of deficiencies in the anchoring of external hazards:
a.
Buildings constructed of unreinforced masonry (URM), except those of less than one thousand and nine hundred (1,900) square feet containing six (6) or fewer occupants.
b.
Buildings constructed prior to January 1, 1935 containing one hundred (100) or more occupants.
c.
Buildings constructed prior to August 1, 1976 containing three hundred (300) or more occupants.
(2)
Exemptions. The following buildings need not comply with this ordinance:
a.
Buildings which have been structurally upgraded in substantial accordance with either the Los Angeles Division 88 Standard for URM buildings of the 1988, or later, edition of the Uniform Building Code.
b.
Buildings whose uses are subject to amortization under this code; provided that, such a building shall be required to be rehabilitates to the then current lateral force requirements in the Uniform Building Code prior to occupancy by a conforming use.
(1)
Building Categories. The categories of buildings with the scope of this ordinance are set forth in Table A, below.
(2)
Owner Notification. The owners of buildings in categories I through III, except those designated as historic buildings, shall be notified within six (6) months of enactment of this ordinance by the Building & Safety Inspection Division of the City of Norco that their buildings are required to have an engineering report submitted to the City. Owners of designated historic buildings, as defined in Chapter 71, shall be notified within eighteen (18) months of enactment of this ordinance.
(3)
Implementation Schedule. The owners of buildings in categories I through III must submit engineering reports with the time frame set out in Table A, below, from the date of mailed notice by the City.
TABLE A | ||
|---|---|---|
CATEGORY | DESCRIPTION | ENGINEERING REPORT SUBMITTED WITHIN DATE OF MAILED NOTICE (IN YEARS) |
I | All URM building | 1 1/2 |
II | All pre-1933 buildings other than URM with 100 occupants or more. | 2 |
III | All building with 300 occupants or more constructed between January 1, 1933 and January 1, 1973. | 2 1/2 |
(1)
Preparation of Reports. Building owners shall employ a civil or structural engineer to prepare the investigation and engineering report outlined below.
(2)
Purpose. To investigate, in a thorough and unambiguous fashion, a building's structural systems that resist the forces imposed by earthquakes and to determine if any individual portion or combination of these systems is inadequate to percent a structural failure (collapse or partial collapse).
(3)
General. Each building shall be treated as an individual case without prejudice or comparison to similar type or age building which may have greater or lesser earthquake resistance. Generalities or stereotypes are to be avoided in the evaluation process by focusing on the specifics of the structural system of the building in question and the local geology of the land on which the building is constructed.
(4)
Level of Investigation. Some buildings will require extensive testing and field investigation to uncover potential structural deficiencies, while others will allow the same level of overall evaluation by a less complicated process due to simplicity of design or the availability of original or subsequent alteration design and construction documents.
It is the responsibility of the engineer performing the evaluation to choose the appropriate level of investigation which will produce a report that is complete and can serve as a sound basis for a conclusion on the collapse hazard the building may present.
(5)
Format for the Report. The following is a basic outline of the format each engineering report should follow. This outline is not to be construed to be a constraint on the professional preparing the report, but rather to provide a skeleton framework within which individual approaches to assembling the information required by the ordinance may be accomplished. It also will serve as a means for the City to evaluate the completeness of each report.
a.
General Information. A description of the building including:
(i)
The street address;
(ii)
The type of occupancy use within the building, with separate uses that generate different occupant loads indicated on a plan showing the square footage of each different use;
(iii)
Plans and elevations showing the location, type and extent of lateral force resisting elements in the building (both horizontal and vertical elements);
(iv)
A description of the construction materials used in the structural elements and information regarding their present condition;
(v)
The date of original construction, if known, and the date, if known, of any subsequent additions or substantial structural alternations of the building; and
(vi)
The name and address of the original designer and contractor, if known, and the name and address of the designer and contractor, if known, for any subsequent additions or substantial structural alterations.
b.
Investigation and Evaluation of Structural Systems. All items to be investigated and the methods of investigation for each type of building under consideration are contained in Appendices A and B, available from the City's Building Inspection Division.
c.
Test Reports. All field and laboratory test results shall be included in the report. Evaluation of the significance of these test results shall be made with regard to each structural system or typical connection being evaluated. This evaluation may be limited to a statement of the adequacy or inadequacy of the system or connection based on the lateral load demand it would be required to resist by calculation. If tests reveal inadequacy, a conceptual solution must be included in the report.
d.
Conclusions. Based on the demand/capacity ratio and the specific evaluation items contained in Appendices A and B, a statement shall be provided explaining the overall significance of the deficiencies found to exist in the building's lateral force resisting system regarding potential collapse or partial collapse failure.
e.
Recommendations. An appropriate solution, which could be used to strengthen the structure to alleviate any collapse or partial collapse threat, shall be specified.
f.
Exceptions and Alternatives. Exceptions to the specific items required to be included in an engineering report may be granted by the chief building official upon review of a written request from the engineer preparing the report. Such a request shall provide evidence that adequate information concerning the required item(s) can be determined by alternate means or that conclusions can be made about the item without following the solution called for in the appropriate appendix. The purpose of granting such exceptions shall be to reduce the costs or disruption that would result from taking required actions, when it can be shown that they are unnecessary to provide information available by other equivalent means. In no case will an exception be granted which would result in an item not being completely evaluated. The decision of the chief building official in granting exceptions is final.
(1)
The City shall utilize the services of civil or structural engineers to assist the Building Inspection Division in determining if the submitted engineering reports conform to the requirements of this chapter.
(2)
The cost of this review shall be recovered by a fee assessed from the building owner based on the time required for the review. This fee amount shall be deducted from the plan checking fee collected for any future construction work that deals directly with correcting any of the structural inadequacies specified in the engineering report.
(3)
Copies of the engineering reports shall be available to interested individuals for a standard copying fee or may be reviewed at the Building Inspection Division offices.
(1)
Notification of Building Tenants. A building owner shall notify all tenants, in writing, that a structural investigation has been performed and that the report is available at the Building Inspection Division offices. This notice must be sent within thirty (30) days of the date the report is submitted to the City.
(2)
Letter of Intent. A building owner shall submit a letter to the Building Inspection Division within one (1) year of the date the engineering report was submitted, indicating the owner's intentions for dealing with any potential collapse hazards found to exist in the building.
The chief building official shall submit a semiannual report to the City Council on the status of the seismic hazards identification program. The reports shall include information regarding the number of buildings analyzed, the severity of the structural inadequacies discovered and any action taken by individual building owners to correct these inadequacies as required by SB547.
It shall be unlawful for the owner of a building identified as being included in the scope of this ordinance to fail to submit a report on either building collapse hazards or external hazards within the time period specifies in Section 1.4, Table A, or to fail to submit a letter of intent within the time period specified in Section 71.4. The following remedies are available to the City:
(1)
The City may seek injunctive relief on behalf of the public to enjoin a building owner's violation of this ordinance.
(2)
A building owner violating this ordinance shall be guilty of a misdemeanor and, upon conviction thereof, shall be punishable by a fine of not more than Five Hundred Dollars ($500) or by imprisonment in the Riverside County Jail for a term not exceeding six (6) months, or by both such fine and imprisonment. Such building owner is guilty of a separate offense for each and every day during any portion of which such violation of this ordinance is committed, continued or permitted by such building owner.[1]
[1]
Editor's Note: Appendix A, Chapter 71 Procedures for Investigation of All Buildings, and Appendix B, Procedures for Investigation of Unreinforced Masonry Bearing Wall Buildings are included as attachments to this title.