Comparative Analysis of Lateral Capacity between Open-Frame and Infill-Frame Systems in a Four-Story Reinforced Concrete Building Using Pushover Analysis

Nyoman Gede Rio Saputra — 2026-09-04

This study aims to compare the lateral capacity and seismic performance of open-frame (OF) and infill-frame (IF) configurations in an existing four-story reinforced concrete residential building in Badung, Bali. A three-dimensional structural model was developed using SAP2000, with identical geometry, material properties, and loading conditions for both configurations. The OF model excluded the lateral contribution of masonry infill, whereas the IF model incorporated existing infill walls using diagonal compression struts. Nonlinear static pushover analysis was conducted to evaluate base-shear capacity, displacement response, interstory drift, and structural performance. The results show that the IF model achieved higher performance-point base shear than the OF model, increasing from 42,144 to 42,855 kN in the X direction and from 43,825 to 44,788 kN in the Y direction. Performance-point displacement also decreased from 98.421 to 94.399 mm in X and from 93.171 to 91.261 mm in Y. Incorporating infill walls reduced interstory drift by approximately 36–58% and improved lateral stiffness, while both configurations remained within the Immediate Occupancy performance level. However, the relatively similar pushover curves indicate that the contribution of infill walls to overall lateral capacity remains limited because of substantial wall openings. The findings demonstrate that infill modeling provides measurable but moderate improvements in structural seismic performance.

Evaluation of Pile Cap Dimensions and Reinforcement Using Conventional, Strut and Tie, and Finite Element Methods

I Putu Gede Putra Gunawan — 2026-08-16

Pile caps play a critical role in transferring axial forces, bending moments, and shear forces from superstructures to pile groups. This study comparatively evaluates the dimensions, reinforcement requirements, and structural response of pile caps with two, three, four, and five piles using the Conventional Method, Strut-and-Tie Model (STM), and Finite Element Method (FEM). The Conventional Method was used to assess flexural and shear capacity in accordance with ACI 318, while STM represented internal load transfer through compression struts and tension ties. Three-dimensional FEM models were developed in ABAQUS using the Concrete Damage Plasticity approach and were validated against a numerical model before analysis. The results show that pile configuration and analytical method significantly affect pile cap dimensions and reinforcement requirements. The five-pile configuration exhibited the largest differences, with STM producing a 1100 mm thick pile cap and 7,645 mm² reinforcement, compared with 900 mm thickness and 5,888 mm reinforcement from the Conventional Method and FEM. FEM produced maximum concrete stresses of 8.20, 2.41, 3.03, and 2.41 MPa for five-, four-, three-, and two-pile configurations, respectively. Reinforcement stresses were generally closer to Conventional Method results. The findings demonstrate that the three approaches provide complementary information for pile cap design and evaluation.

International Journal Papier Advance and Scientific Review

Comparative Analysis of Lateral Capacity between Open-Frame and Infill-Frame Systems in a Four-Story Reinforced Concrete Building Using Pushover Analysis

Evaluation of Pile Cap Dimensions and Reinforcement Using Conventional, Strut and Tie, and Finite Element Methods