This information is provided free of charge by the Department of Industrial Relations from its web site at www.dir.ca.gov. These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at http://www.dir.ca.gov/od_pub/disclaimer.html.


Subchapter 6. Elevator Safety Orders
Article 18. Design Data, Formulas, Tests on Approved Devices, and Electrical Regulations

Return to index
New query

§3111. Stresses and Deflection in Machinery and Sheave Beams and Their Supports.

(a) Allowable Loads and Stresses for Beams and Floors.

(1) The stresses shall not exceed 80 percent of those permitted for static loads.

(A) Structural steel by AISC Specification for Design Fabrication and Erection of Structural Steel Building.

(B) Reinforced concrete by ANSI A89.1 Concrete Building Code Requirements for Reinforced Concrete.

(2) The stresses in overhead beams, floors, and their supports shall be based on not less than the sum of the following loads:

(A) The load resting on the beams and supports, which shall include the complete weight of the machine, sheaves, controller, governor, and any other equipment, together with that portion, if any, of the machine room floor supported thereon.

(B) Twice the sum of the tensions in all wire ropes passing over sheaves or drums supported by the beams with rated load in the car.

NOTE: These tensions are doubled to take care of impact accelerating stresses, etc.

(3) The stresses in beams, foundations, and floors for machinery and sheaves not located directly over the hoistway shall be based on not less than the following loads:

(A) The foundation shall support the total weight of the machine, sheaves, and other equipment, and the floor, if any.

(B) The sheave beams and the foundation bolts shall withstand twice the vertical component of the tensions in all hoisting ropes passing over sheaves or drums on the foundation or beams, less the weight of the machine or sheaves.

(C) The sheave beams and the foundation bolts shall withstand twice the horizontal component, if any, of the tensions in all hoisting ropes passing over sheaves or drums on the foundation or beams.

(D) The foundation shall withstand twice the turning moment, if any, developed by the tensions in all the hoisting ropes passing over sheaves or drums on the foundation or beams.

(4) Where stresses due to loads, other than elevator loads, supported on beams or floor exceed those due to elevator loads, 100 percent of the permitted stresses may be used.

(b) Allowable Deflections. The allowable deflections of machinery and sheave beams, and their immediate supports under static load, shall not exceed 1/1666 of the span.

(c) Bolts and Rivets.

(1) Anchor bolts for machines or sheaves located below or to one side of the hoistway shall conform to ASTM A307.

(A) Total tension in anchor bolts shall not exceed 12,000 pounds per square inch of net section.

(B) Total shear in anchor bolts shall not exceed 8,600 pounds per square inch of actual area in the shear plane.

EXCEPTION: Bolts made of steel having greater strength than specified by ASTM A307 may be used and the maximum allowable stresses increased proportionately based on the ratio of ultimate strengths. Elongation shall conform to the requirements of the corresponding ASTM specification.

(2) Bolts or rivets used to secure overhead hoisting rope hitch plates shall conform to ASTM A307 and ASTM A502 respectively.

(A) Where bolts or rivets are subjected to shearing stresses due to tension in the hoisting ropes, the total shear shall not be more than 8,600 pounds per square inch of actual area in the shear plane. The stresses in welds shall not be more than 8,000 pounds per square inch based on the throat area of the welds.

EXCEPTION: Bolts made of steel having greater strength than specified by ASTM A307 may be used and the maximum allowable stresses increased proportionately based on the ratio of ultimate strengths. Elongation shall conform to the requirements of the corresponding ASTM specification.

(3) The fastenings used to attach equipment, except rail brackets, to the supporting structure shall be designed to withstand seismic forces of 1.0 g. horizontally and 0.5 g. vertically acting simultaneously when such fastenings are rigid or when fastenings use rubber or similar material for vibration isolation of equipment. Fastenings using springs for vibration isolation of equipment shall be designed to withstand forces double those for rigid fastenings.

The stresses in parts or structural members made of steel shall not exceed 88% of the yield strength of the material used in the fastenings.

(d) Hitch Plates and Hitch Plate Supports. Total stresses in tension, plus bending in hitch plates and in hitch plate shapes, shall not be more than 12,000 pounds per square inch. The hitch plate supporting beams shall be designed to withstand twice the sum of the tensions in all the hoisting ropes attached to the hitch plates.

(e) Cast Metals in Tension or Bending. Cast metals having an elongation of less than 20 percent in a length of 2 inches, which are subject to tension or bending, shall not be used to support machinery or equipment from the underside of overhead beams or floors.

HISTORY

1. New subsection (c)(3) filed 9-5-75; effective thirtieth day thereafter (Register 75, No. 36).

2. Amendment of subsection (a)(1) filed 6-23-77; effective thirtieth day thereafter (Register 77, No. 26).

3. Subsection (c)(3) which was filed 9-5-75 (Register 75, No. 36), was approved by the Building Standards Commission 3-26-76. History note printed in Register 78, No. 30 for technical reasons.

4. Editorial corrections (Register 95, No. 34).

Go BackGo Back to Article 18 Table of Contents