PSI - Issue 70

Anchal kaw et al. / Procedia Structural Integrity 70 (2025) 161–168

165

Eurocode 8 (Design of structures for earthquake resistance) Part 1 provides guidelines for the seismic design of NSEs It clearly specifies that NSEs as well as their attachment, supports and anchorages must be seismically resistant. It considers the effect of time period of both NSEs and SEs while calculating lateral forces acting on NSEs in a building during a seismic event. It provides more realistic approach to calculate the lateral forces acting on NSEs rather than Indian seismic codes which underestimate the seismic demand. 3.2. Building Typology Consideration A G+3 Hospital and commercial building located in Seismic zone V in India is selected and analyzed. The overall height of both buildings is 12 m and the height of each floor is taken as 3 m. The length of the hospital building is 33.07 m and length of commercial building is 25 m. To understand the impact of lateral forces acting on NSEs during an earthquake, six non-structural elements are selected on each floor of hospital building (multiple pipes, firefighting system, HVAC duct system, cable tray, pneumatic pipes, oxygen pipes). In case of commercial building four non structural elements are considered on each floor (multiple pipes, firefighting system, HVAC duct system, cable tray). The weight per unit length of these NSEs is tabulated below in Table 2.

Table 2. Weight per unit length of NSEs (source-public domain) Non-structural elements (NSEs)

Weight per unit length

Multiple pipes Pipe size (200 NB) Pipe size (100 NB) Firefighting system

0.673 kN /m 0.194 kN/m

Pipe size (150 NB)

0.388 kN/m 0.550 kN/m 0.588 kN/m 0.0052 kN/m 0.021 kN/m

Cable tray (450mm) HVAC Duct system Oxygen pipe (22mm Outside Diameter with 0.9 mm thickness) Pneumatic pipes

The formula from Eurocode 8(EN 1998-1: Eurocode 8: Design of structures for earthquake resistance – Part 1: General rules, seismic actions and rules for buildings, 2004) and IS 16700:2023(Standard, n.d.) is used for the calculation of total lateral forces acting on these NSEs in both hospital as well as commercial buildings. The same assumptions are taken for both Eurocode 8 and IS 16700 calculations regarding the weight, height and location of NSEs. Similar soil conditions (hard soil), support system and connection details are considered to ensure a fair comparative analysis. A comparative analysis of these lateral forces acting on the utility systems is prepared by making use of the respective formula from Eurocode 8 and Is 16700:2023. The design lateral force acting on acceleration sensitive NSEs as per IS16700:2023 is calculated from the formula given below. = (1+ ℎ ) (1) where I Z = R = p Im S = e p i c o s o m rt m a ic p n z o c o e n n e fa e n c t f t a r o c e r t s o r p r a onngsees mf r oo dmi f i2c at ot i o2 n. 5 f da ce tpoernrdai nn gg i no gn fi rmo pmo r1t at on c3e. 5o f N S E s Wapp == wcoemigphotnoefnNtSaEmplification factor ranging from 1 to 5 x = height of NSEs above the level of application of seismic action h = overall height ofbuilding The lateral force acting on NSE for the seismic design of these elements as per Eurocode 8 is calculated from the formula given below.