§ 27-670 Lateral loads.
AC § 27-670
(a)Earth and ground water pressure. Every foundation wall or other wall serving as a retaining structure shall be designed to resist, in addition to the vertical loads acting thereon, the incident lateral earth pressures and surcharges, plus hydrostatic pressures corresponding to the maximum probable ground water level. Retaining walls shall be designed to resist at least the superimposed effects of the total static lateral soil pressure, excluding the pressure caused by any temporary surcharge, plus an earthquake force of 0.045 wsh2 (horizontal backfill surface), where ws equals unit weight of soil and h equals wall height. Surcharges which are applied over extended periods of time shall be included in the total static lateral soil pressure and their earthquake lateral force shall be computed and added to the force of 0.045 wsh2. The earthquake force from backfill shall be distributed as an inverse triangle over the height of the wall. The point of application of the earthquake force from an extended duration surcharge shall be determined on an individual case basis. If the backfill consists of loose saturated granular soil, consideration shall be given to the potential liquefication of the backfill during the seismic loading using reference standard RS 9-6.
(b)Wind and other superstructure loads. Provision shall be made to resist lateral loads imposed on the superstructure due to wind or other causes.
(c)Soil movements. Buildings shall not be constructed in areas where the soil is subject to lateral movements unless positive provision is made to prevent such movements. Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 1995/017.
