Dynamic Soil Structure Interaction of a High-Rise Building Resting over a Finned Pile Mat

Abstract

High-rise building safety is generally supported by pile-mat systems. They must be sturdy enough to withstand potential lateral loads brought on by earthquakes, wind, dredging, and machine vibrations, in addition to increased axial loads. An innovative piled-mat foundation system is required to deal with these impacts because standard pile foundation systems only have lateral capacities that are 10% of their axial capacities. This study aims to reduce the damage caused by seismic impacts on high-rise buildings using shear walls supported by piled mats, thereby minimizing vibrations within the structure. Compared with conventional pile systems, the finned-pile foundation is a proven method that can withstand a 65% to 80% higher lateral load; hence, a series of SSI analyses were performed on a 25-story high-rise building, with the shear wall resting on a finned-pile mat (FP-Mat), under a far-field earthquake excitation, using ABAQUS software. The seismic responses were studied by performing a time–history analysis on the FP-Mat, with varying fin-lengths (Lf) of 0.2Lp, 0.4Lp, 0.6Lp, and 0.8Lp, which was compared with an analysis of a conventional piled-mat (RP-Mat). The seismic responses for RP-Mat and FP-Mats were studied with peak-acceleration, maximum horizontal displacement, and inter-story drifts acting as the damage parameters. The provision of FP-Mats significantly reduced the vibrations and seismic effects on the building, and as the fin-length increased, the vibrations and seismic effects reduced further. The drifting bound was also reduced as the fin-length increased. The optimum fin-length for FP-Mats is suggested to be 0.6Lp in terms of seismic performance and construction efficiency. This study helps one understand the seismic behaviors of high-rise buildings resting on finned pile mats.

Soil-Structure Interaction Assessment for Seismic Performance of High-Rise RC Building on Piled-Raft Foundation

“…Using the direct approach requires employing a computer program that can simulate the behavior of both structure and soil with equal rigor simultaneously [21]. Plaxis 3D software package [13] was used to perform dynamic analyses for soilstructure interaction problems in which the Rayleigh coefficients, mass damping factors (α=0.758,0.284) and stiffness damping factors (β=0.012,0.024) considering El-Centro and Hachinohe earthquakes, respectively, were calculated taking into account the frequency-dependent damping that forms the different modes comprising the soilfoundation [2,3]. Soil elements, structural elements as shown in Fig.…”

“…The software considered the lateral and buckling behavior of the piles by default. In most of geotechnical simulations, the interfaces strength reduction factor (Rinter) of 0.75 was used to reduce the interface's shear strength [3]. Several researchers [2,3] have employed the adopted non-linear elastic-perfectly-plastic Mohr-Coulomb model to represent the dynamic SSI with aim of simulating the soil behavior under seismic loads.…”

“…The superstructure is founded on low compressible SILTpoorly graded SAND and the bedrock depth is 95m. This utilized geotechnical characteristics of the subsoil [3] are shown in Table 3. By employing ECP 202-2007 [19], the pile base resistance (Fmax), axial skin resistance (Fskin), and bearing capacity (Npile) in such φ-c soil are summarized in Table 4.…”

“…The notable damages caused by the earthquakes that occurred in some cities, such as those in Mexico City 1985, Fukushima 2011, and Christchurch 2011, and other recent earthquakes, demonstrate the fact that local soil properties can play a significant role in determining seismic response of the structures under the earthquakes' motions. To solve soil-structure interaction problems, there are two main methods; the direct method [1][2][3] and the substructure method [4][5][6]. The Modelling of foundations and superstructures is generally found to be more straightforward and less complicated in comparison to the soil medium underneath [7].…”

A Coupled Finite-Boundary Element Method for Efficient Dynamic Structure-Soil-Structure Interaction Modeling

“…For example, researchers have used FEA to analyze the effects of SSSI and SSI on tall buildings during earthquakes and fount that adjacent buildings can significantly affect each other's behavior due to soil movement and deformation [10]. Bariker and Kolathayar [18] have employed the FEA method to analyze a new foundation construction. Other studies have looked at the effects of SSSI on underground structures such as tunnels, finding that soil-structure interaction can cause significant stress and deformation in the tunnel [19,20].…”