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This study was done to select the appropriate vibration standard to be the adopted vibration standard for a construction project that was located in adjacent to many buildings. These buildings may be affected by project activities induced vibrations.
Citations
... Olusola (2018) evaluated and predicted the responses of adjoining structures to blast-induced ground vibrations due to Kopek construction. Ahmed (2018) used the dynamic analysis of site vibration to select a suitable vibration standard for estimating the level of damage on buildings subjected to construction-induced vibration. Stolarik et al. (2019) presented a theoretical study and original results concerning the seismic load on historical and dilapidated buildings in brownfield areas due to the ground-borne vibration caused by mechanized construction works. ...
Ground vibrations caused by the construction of impact drilling piles may affect adjacent bridges, so corresponding prediction and monitoring are necessary to ensure the safety of bridges. In this study, the construction near an existing long-span double-convex arch bridge is taken as a case study to investigate different layouts of construction machines emanating harmful ground vibrations to the existing adjacent bridge by numerical simulations and monitoring. The peak acceleration and velocity acquired from numerical simulations, and monitoring were successfully used to implement impact drilling pile construction near the existing bridge. The results show that there are good consistencies between the monitoring and numerical simulation results, and the vibration acceleration of the foundation of abutments and piers are mainly derived from the vibration caused by the construction within a distance of 50 m, while the construction beyond 50 m has little effect on the old bridge. The numbers and locations of machines near the same foundation may have a weakening or strengthening effect on the peak acceleration and velocity due to destructive and constructive interference of waves, which can help to control the effects of the vibrations of the existing adjacent bridge.
... Besides, there are many researches focus on the study and analysis of traffic-induced vibration through field test data. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] However, as the authors know, none of analyses be compared and discussed on the differences of amplitude in frequency domain generated by the selection of different time periods. Thus, the difference of amplitude may result in opposite conclusion of the vibration impact on the facilities, even though, it may get into controversial lawsuits/legal issues later. ...
The precision tools equipped with active vibration isolation platform in high-tech facilities are sensitive to low-frequency vibration. Currently, there are neither standards nor rules to select the time period of vibration data for conducting the spectral analysis of low-frequency vibration, and none of the analyses can be used to compare and discuss the differences of spectral amplitude generated by the selection of different time periods. Therefore, to estimate the amplitude of low-frequency vibration, the spectral analysis at low-frequency range is crucial. This paper is to elaborate the spectral analysis procedures on various band widths by using zero-padding on the vibration signal in low-frequency band. The mechanism not only facilitates to obtain more reliable result but also to lay a common base for comparison from different user. Finally, the in situ measurement data, including high-speed train-induced low-frequency vibration, are used to exemplify the length of time period affects the results of spectral analysis, either on narrowband or one-third octave band analysis.
... In particular, the excavation activities, involving the removal of soil and rock through blasting or mechanical tools, can induce dynamic loads on the adjacent structures, and the generated ground vibrations may have detrimental effects on the residents in the surrounding environment [2,3]. For this reason, when the excavation works are located in an urban area, the adoption of non-explosive mechanical methods, such as hydraulic breaker hammers, can be more convenient, as they have a lower impact on the sensitive receptors on the ground surface. ...
... The pcpv 0 of the control point was compared with the threshold (pcpv lim ) fixed by the technical standard to 0.05 m/s [22], verifying that pcpv 0 < pcpv lim (3) • Two FE analyses conducted using as input motion at the base of the building the vertical time histories recorded at a distance of 10 m for the Scenarios 2 and 3. The control points were assumed in the center of the mass of each floor (i.e., nodes 70, 73, 76, 76, 82, 85 for the first storey and nodes 86, 91, 94, 98, 100, 103 for the second storey), as shown in Figure 9. ...
The paper describes the numerical approach adopted to investigate the effects of vibrations induced on reinforced concrete (R.C.) buildings by the excavation works needed to bury an existing railway line crossing an urban area in the south of Italy. The construction works are carried out in dolomitic rocks, characterized by a high resistance to excavation. Therefore, they may have a great impact on the surrounding environment in terms of induced vibrations. The study is conducted through an uncoupled approach, investigating the dynamic response of the geotechnical system and the above-surface structure, separately. The impulse force equivalent to the dynamic action of a breaker hammer is used as input motion for 2D finite element (FE) geotechnical simulations of the wave propagation process occurring during the excavation. Then, the acceleration time histories obtained from the geotechnical analyses are adopted to study the dynamic performance of an “index” R.C. building, representing the most recurrent structural typology in the examined area, through a 3D FE model. The results show how the adoption of a mitigation strategy consisting in the execution of a preliminary vertical cut followed by a rock crushing treatment allows to significantly reduce the vibrations induced by the excavation processes on existing buildings.
The Target tracking or command following problems involving both constant and time-varying reference inputs are quite common in control theory and have a wide range of applications in the field of aerospace and electrical engineering. This approach is extended to civil engineering applications, especially to achieve the desired synchronization for real-time hybrid simulation (RTHS). This study presents that, active-control based tracking problem can also be extended to base-isolated buildings in reducing the bearing displacement of the isolator and the floor drift of super-structure during external excitations. In addition, the efficacy of the algorithm can be justified in terms of tracking a wide range of frequency inputs, while mitigating the influence of sensor noise.For the tracking of reference input, an integrator is preferred in parallel with the proportional (PI) controller for the reduction of both transient and steady-state
error signals. Present study proposes a full and reduced order robust PI controller (termed as controller-T) such that, the tracking problem is generic for a wide range of frequency inputs. In this case, the controller-observer framework is designed through sub-optimal H_∞ optimal control algorithm. The uncertainties in the closed-loop system involves norm-bounded parametric perturbation of the structural system parameters. First, the tracking efficiency of PI controller with respect to sub-optimal H_∞ based P controller, without the integral part (denoted as controller-H) is discussed in terms of reduction in root mean square (RMS) values of: (i) control force and (ii) error signal of a SDOF spring-mass-damper system. Finally, it has been clearly stated that the application of the proposed robust tracking problem can have a significant futuristic application in the field of hybrid control of base-isolated structures during strong seismic events. It is envisioned that the proposed approach for tracking problem is quite effective in protecting the structural members and the attached essential non-structural components during ground shaking.
The conference proceedings contain full-length keynote and general articles presented at the International Conference on Futuristic Technologies 2021 (FT 21), held in online mode during 22-24 January 2021. This conference was organized by Smart Structures and Dynamics Laboratory (SSDL), Indian Institute of Technology Delhi and partnered by Futuristic Technologies of India.
The keynote papers are grouped under one heading and the general papers are categorized into nine domains, namely, Futuristic Structural Health Monitoring, Futuristic Dynamics, Metamaterials, Futuristic Construction Materials, Futuristic Retrofitting, Futuristic Energy Solutions, Futuristic Biomedical and Other applications, Artificial Intelligence and Futuristic Structural Materials..
It is hoped that these proceedings will be a benchmark for the grooming researchers and practicing engineers.
