Finite Element Investigation of Optimal Reinforced Concrete Shear Wall Placement for Vibration Mitigation in Adjacent Buildings with Open-Trench Isolation

Abstract

Vibration transmission in coupled soil--structure systems remains a fundamental challenge in the serviceability and resilience assessment of reinforced concrete (RC) buildings subjected to external dynamic excitations. Among the various sources of ground-borne vibration, railway-induced excitation constitutes a particularly significant engineering concern due to the continuing expansion of urban rail transportation networks and the increasing proximity of buildings to railway infrastructure. Motivated by this practical problem, the present study investigates the combined effectiveness of open-trench wave barriers and optimized shear wall placement for vibration mitigation in RC buildings subjected to railway-generated ground motion.

A two-dimensional plane-strain finite element framework was developed in ABAQUS to simulate the fully coupled soil--track--structure interaction problem. The computational model consists of a six-story RC frame structure founded on layered soil, a railway embankment subjected to dynamic excitation, and a 3~m-deep open trench positioned between the vibration source and the structure. To examine the influence of stiffness redistribution on structural vibration characteristics, four structural configurations were considered, including a reference model without a shear wall and three additional cases incorporating a 0.30~m-thick RC shear wall located in the first, second, and third structural spans, respectively. The numerical framework was verified against established benchmark studies for ground-borne wave propagation and dynamic soil--structure interaction.

Structural vibration response was evaluated at multiple roof-level monitoring locations using peak particle velocity (PPV), root mean square velocity (RMS), and vibration decibel level (VdB). The results demonstrate that the open trench effectively attenuates incident wave energy before interaction with the structure, while the incorporation of strategically positioned shear walls further suppresses vibration transmission through enhanced global stiffness and altered dynamic load-transfer mechanisms. Among the investigated configurations, the shear wall located in the third span, corresponding to the span farthest from the excitation source, exhibited the highest mitigation efficiency, yielding reductions of up to 30.7\% in PPV, 13.8\% in RMS response, and 2.05\% in VdB. The observed reductions indicate a substantial decrease in structural vibration demand and highlight the importance of stiffness distribution in controlling dynamic response characteristics.

The findings reveal a pronounced synergistic interaction between path-based isolation and receiver-based structural stiffening mechanisms and provide a mechanics-based framework for the vibration-resilient design and optimization of RC buildings subjected to externally induced ground vibrations.