4.1.3.4.Serviceability

(1) A building and its structural components shall be checked for serviceability limit states as defined in Clause 4.1.3.1.(1)(a) under the effect of service loads for serviceability criteria specified or recommended in Articles 4.1.3.5. and 4.1.3.6. and in the standards listed in Section 4.3. (See Note A-4.1.3.4.(1)) (2) The effect of service loads on the serviceability limit states shall be determined in accordance with this Article and the load combinations listed in Table 4.1.3.4., the applicable combination being that which results in the most critical effect. (3) Other load combinations that must also be considered are the principal loads acting with the companion loads taken as zero. (4) Deflections calculated for load types P, T and H, if present, with load factors of 1.0 shall be included with the calculated deflections due to principal loads. (5) The determination of the deflection shall consider the following: (a) for materials that result in increased deformations over time under sustained loads, the deflection calculation shall consider the portion of live load, L, that is sustained over time, Ls, and the portion that is transitory, Lt, and (b) the calculated deflection due to dead load, D, and sustained live load, Ls, shall be increased by a creep factor as specified in the standards listed in Section 4.3. to obtain the additional long-term deflection. (6) The determination of the long-term settlement of foundations shall consider the following: (a) for foundation soil types that result in increased settlement over time under sustained loads, the additional long-term settlements shall be determined for the portion of live load, L, that is sustained over time, Ls, and the portion that is transitory, Lt, and (b) the additional long-term settlements due to dead load, D, and sustained live loads, Ls, shall be calculated from the foundation soil properties provided by a qualified professional geotechnical engineer. Table 4.1.3.4. Loads and Load Combinations for Serviceability Forming Part of Sentence 4.1.3.4.(2) Load Combinations Limit State Structural Parameter Load Case Principal Loads Companion Loads Deflection of the structure 1 1.0D + 1.0L 0.3W or 0.35S Deflection for materials or of components of the 2 1.0D + 1.0W 0.35L(2) or 0.35S not subject to creep structure(1) 3 1.0D + 1.0S 0.3W or 0.35L(2) Total deflection of the 1 1.0D + 1.0Ls(4) + 1.0Lt(5) 0.3W or 0.35S Deflection for materials structure or of 2 1.0D + 1.0W 0.35L(2) or 0.35S subject to creep components of the structure(3) 3 1.0D + 1.0S 0.3W or 0.35L(2) Vibration serviceability Acceleration (6) Notes to Table 4.1.3.4.: (1) The calculated deflection due to dead load, D, is permitted to be excluded where specified in the standards listed in Section 4.3. (2) The companion load factor of 0.35 for live load, L, shall be increased to 0.5 for storage areas, equipment areas and service rooms. (3) The calculated immediate deflection due to dead load, D, is permitted to be excluded where specified in the standards listed in Section 4.3. (4) Ls = sustained portion of the live load, L. (5) Lt = transitory portion of the live load, L. (6) See Note A-Table 4.1.3.4.