*Natural Hazards - Impacts, Adjustments and Resilience DOI: http://dx.doi.org/10.5772/intechopen.94303*

#### **Figure 11.**

*Ultimate compression strain in concrete (EC8):*

*Natural Hazards - Impacts, Adjustments and Resilience*

*Ash* = area of confinement reinforcement

*cc* = confined compressive strength of concrete

**4.2 Tools for section analysis of building elements**

to compare the performance limits (refer **Figures 10**–**12**).

**4.3 Mapping of section analysis using design tools and design codes**

*f* ,

**Figure 10.**

**220**

*fl* = confining pressure

*εcu* ¼ 0*:*004 þ 1*:*4*ρ<sup>s</sup> f yhεsm= f*

The section analysis of confined concrete is dependent on the type of detailing done for beams and columns which undergo in-elastic deformations. ETABS software uses *Mander*-model for confined concrete to estimate increased strength due to lateral reinforcements. However, without complete detailing of the column reinforcement it is not suitable to directly assume the performance. Hence, it is suitable to use a separate tool to generate (*M* � *φ*) and (*σ* � *ε*) plots and the results of which can be uploaded in ETABS software to give more accuracy in terms of overall performance of building. The two such tools are RCA and SEMAp, which are used

The mapping of threshold limits using design tools and codes gives an envelope for comparison. The ultimate rotation (*θu*) is sum of yield rotation (*θy*) and plastic rotation (*θp*). The length of plastic hinge is taken as 0.5D and absolute concrete strain (*εcu*) is calculated [20, 21]. It is observed that for IS designed building, the

*Section analysis results for RC column designed as per IS code. (a) M* � *φ curve as per RC analysis tool for column designed as per IS code. (b) M* � *φ curve as per SEMAp tool for column designed as per IS code.*

,

*cc* (6)

*Section analysis results for RC column designed as per ACI-318 code. (a) M* � *φ curve as per RC analysis tool for column designed as per ACI-318 code. (b) M* � *φ curve as per SEMAp tool for column designed as per ACI-318 code.*

#### **Figure 12.**

*Section analysis results for RC column designed as per EC8 design code. (a) M* � *φ curve as per RC analysis tool for column designed as per EC8 design code. (b) M* � *φ curve as per SEMAp tool for column designed as per EC8 design code.*


#### **Table 3.**

*Section analysis using design tools and design codes (limits mapping).*

pattern in the following part are discussed to encompass: hinge results, hinge

*Comparison of reinforcement in columns. (a) IS code design. (b) ACI-318 code design. (c) EC8 design.*

• The building designed as per Indian Standard codes lead to higher performance in terms of overall capacity of building owing to section sizes and higher rebar requirements. The distribution of steel is better in building designed using

• The concept of formation of hinges in columns is not appreciated by seismic design engineers for which the beam to column capacity ratio is maintained in all seismic design codes viz. 1.2 in ACI and 1.4 in IS-13920. Hence, strong column-weak beam is the basic philosophy followed by all codes in different

• It was found that the building designed using IS code resulted in the formation of hinges in columns and the failed columns were at the GF, 3rd, 4th and 5th storey (refer **Figure 5a**). The hinge locations for three designs are given in

locations, performance point and element level indexes.

*Natural Hazards - Impacts, Adjustments and Resilience DOI: http://dx.doi.org/10.5772/intechopen.94303*

ACI-318 and EC-8 (refer **Figure 14**).

capacities (refer **Figure 15**).

**Figure 14.**

**223**

**5.1 Comparison of design codes on building performance**

**5.2 Comparison based on nonlinear static analysis in ETABS**

percentage of steel in the building elements: **Case 1:** IS-1893 V (kN): 7200 D (mm): 430

**Figure 16**. The performance point is compared in **Figure 17**.

• The capacity of building designed as per IS code is higher due to higher

#### **Figure 13.**

*Comparison of moment (M) at yield and ultimate state for column C19.*

results of RCA and SEMAp are matching in terms of moments (**Table 3**; [5]). The results of ultimate strain limits for NC-PL of EC-8 and SEMAp are matching (**Table 3**; [9]). Similarity is there in ultimate rotation values of RCA and SEMAp (**Table 3**; [10]). The ultimate rotation values of columns designed using ACI-318 and EC-8 are found to be in similar range and are higher than rotation limit of IS designed building (**Table 3**; [10]). The variation in moments for all cases is shown in **Figure 13**.
