scholarly journals Research on the Influence of Variable Stiffness Levelling Piles on Differential Settlement of High-rise Buildings

Author(s):  
Yufeng Yang ◽  
Tengjun Gan
2011 ◽  
Vol 243-249 ◽  
pp. 2498-2502 ◽  
Author(s):  
Yong Le Li ◽  
Jiang Feng Wang ◽  
Qian Wang ◽  
Kun Yang

The finite element calculation results indicated: interaction of the superstructure-the pile raft foundation-foundation, the stress of the pile raft foundation appeared "disc type" distribution, namely, was big in the middle, and was small in the edge. Generation of differential settlement was due to the upper structure secondary stress and raft internal force. Through adjusting the foundation soil stiffness and pile length, pile diameter and pile distance, the influence of variable stiffness on differential settlement was analyzed. The results showed that changing the pile arrangement and adjusting the stiffness of foundation soil was optimal scheme of the pile raft foundation in high-rise building.


Author(s):  
Motoichi TAKAHASHI ◽  
Takuji KOBORI ◽  
Tadashi NASU ◽  
Akihiro KUNISUE

Author(s):  
Qingshan Yang ◽  
Yu Yang ◽  
Qi Wang ◽  
Liuliu Peng

Constructing bridge towers are high-rise and flexible structures subjected to significant wind induced vibrations. Tuned Mass Dampers (TMDs) have been widely used to reduce dynamic responses of high-rise structures under fluctuating wind loadings. By resonance with main structure, TMD can effectively suppress structural vibrations. However, the natural frequencies of bridge tower usually decrease continuously during its construction progress. The frequency shift characteristic will cause the detune of TMD, leading to a great control efficiency loss. As a novel stiffness tunable device made of magnetorheological elastomer (MRE), MRE-TMD can adjust its natural frequency in real-time to track the main structure, avoid detuning and achieve better control performance. To study the wind induced vibration control performance of MRE-TMD, this paper explores the fluctuating wind responses of constructing bridge towers in along wind and cross wind directions. The fluctuating wind loads are generated by harmonic superposition method with the along wind fluctuating wind speed spectrum and the empirical power spectrum of fluctuating lift force. By comparing among the uncontrolled, TMD controlled and MRE-TMD controlled constructing bridge towers, the simulation results show that the MRE-TMD system can effectively maintain the tuning state, and significantly reduce the wind induced vibrations during whole construction process.


2012 ◽  
Vol 174-177 ◽  
pp. 1913-1916
Author(s):  
Shu Qing Guo

In order to minimize the final differential settlement and improve the mechanics performance of high-rise buildings and its podium, some pile design concept for the tower-podium connected building is discussed in this paper. According to the interaction of superstructure-foundation-pile, the pile rigidity of tower area (the core area) is enhanced, and that of outer podium area is weakened in the optimal pile design. This measure is applied in some projects with good technical result and economical effects.


2020 ◽  
Vol 29 (9) ◽  
Author(s):  
Zheng He ◽  
Yi Lu ◽  
Fengning Liu ◽  
Feng Pan ◽  
Shuaishuai He

2017 ◽  
Vol 8 (2) ◽  
pp. 210-221 ◽  
Author(s):  
Lan Lin ◽  
Adel Hanna ◽  
Anup Sinha ◽  
Lucia Tirca

Purpose Differential settlement between foundations’ elements induces additional stresses in the structural elements. In general, the amount of settlement that a structure can undergo without distress is large, provided that the structure settles uniformly. However, based on the fact that the soil under the foundation may not be uniform in nature and the loads transferred from the superstructure to the foundation are variable, differential settlements between the foundation elements are expected. The purpose of this paper is to evaluate the stresses induced in a typical ten-storey reinforced concrete building subjected to excessive differential settlement. Design/methodology/approach In this investigation, excessive differential settlement up to 75 mm is assigned to the center column on the ground floor that represents the most critical case. A three-dimensional finite element model is developed to perform structural analysis using the software SAP2000, and the nonlinear static pushover analysis is performed. Findings The results of this study show that the building behaves elastically up to 25 mm of differential settlement between its foundation elements, which agrees well with the recommendation given in design manuals. Beyond this value, significant inelastic response is observed in the lower floors and decreases gradually in the higher floors and accordingly, some members have consumed the factor of safety and are in the verge of failure. Originality/value Based on the results of this study, recommendations are made for better communication between the structure and the geotechnical engineers to either limit the differential settlements or incorporate these additional stresses during the design stage of the building. Furthermore, the results of the study can be used to recommend to building codes or design manuals to add a load component due to the anticipated differential settlements of the foundation.


2019 ◽  
Vol 22 (13) ◽  
pp. 2727-2740
Author(s):  
Yanqing Xu ◽  
Tong Guo ◽  
Ping Yan

The triple friction pendulum bearing, as a novel seismic isolator, has received much attention due to its notable advantages such as variable stiffness and damping; however, existing investigations and applications are mainly for low-rise or medium-rise buildings. In order to determine optimal design parameters of triple friction pendulum bearings for high-rise buildings, equations of motion for an isolated high-rise building are derived, and an evaluation function is developed to indicate the isolation effect with different pendulum parameters. In the optimization analysis, seven ground motions are scaled to three levels (corresponding to the service level, the design basis, and the maximum considered earthquakes, respectively) and the genetic algorithm is applied to determine the optimal pendulum parameters. The optimization results are compared with those obtained by the single-degree-of-freedom model, where significant difference is observed, showing the necessity of the presented study. Using the optimal parameters of triple friction pendulum bearings, seismic responses of the isolated building are analyzed and compared with those of the building isolated using the single friction pendulum bearings and the base-fixed building, where it is observed that the triple friction pendulum bearing is more effective and reliable in reducing base shear, floor acceleration, and story drifts.


Author(s):  
Steven A. Lavender ◽  
Jay P. Mehta ◽  
Glenn E. Hedman ◽  
Sanghyun Park ◽  
Paul A. Reichelt ◽  
...  

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