Control methods based on the theory of variable structure system or sliding mode control are presented for applications to seismically excited nonlinear and hysteretic civil engineering structures. These robust with respect parametric uncertainties structure. The controllers have no adverse effect should actuator be saturated due unexpected extreme earthquakes. Emphasis is placed continuous that do not possible chattering effects. Static output feedback using only measured information from a...

Based on the theory of continuous sliding-mode control, control methods are presented for seismic-excited buildings isolated by a frictional-type sliding-isolation system. The dynamic behavior building equipped with base-sliding-isolation system is highly nonlinear, and sliding-mode–control method ideal such nonlinear systems. In addition to full-state-feedback controllers, simple static-output-feedback controller using only measured information from few sensors installed at strategic...

Abstract Vertical deformation can be revealed by various techniques such as precise leveling, satellite imagery, and extensometry. Despite considerable effort, recording detailed subsurface using traditional extensometers remains challenging when attempting to detect localized deformation. Here we introduce distributed fiber optic sensing based on Brillouin scattering a geophysical exploration method for imaging profiles of vertical By examining cable‐soil interaction found threshold in...

Continuous sliding mode control (CSMC) methods, which do not have an undesirable chattering effect, are presented for applications to seismically excited linear structures. These methods robust with respect parametric uncertainties of the structure. The controllers no adverse effect should actuators be saturated due unexpected extreme earthquakes. Static output using only a limited number sensors without observer also presented. When controller is installed in each story unit building,...

Abstract Recently, several hybrid protective systems have been explored for applications to seismic‐excited bridge structures. In particular, two types of aseismic shown be quite effective: (i) rubber bearings and variable dampers (or actuators), (ii) sliding actuators. this paper, control methods are presented these systems. The based on the theory structure system (VSS) or mode (SMC). Emphasis is placed static (direct) output feedback controllers using only information measured from a few...

Understanding the spatiotemporal evolution of overburden deformation during coal mining is still a challenge in engineering practice due to limitation monitoring techniques. Taking Yangliu Coal Mine as an example, similarity model test was designed and conducted investigate failure mechanism overlying rocks this study. Distributed fiber optic sensing (DFOS), high-density electrical resistivity tomography (HD-ERT) close-range photogrammetry (CRP) technologies were used for comprehensive...

In this letter, a broadband and wide-angle linear-to-circular polarization converter (LCPC) based on three-layer transmissive metasurface is proposed, to solve the problem of efficiency degradation caused by mismatch in mobile microwave wireless power transmission (MWPT). The simulated results show that our proposed model has an axial ratio (AR) less than 3 dB 4.24-6.24 GHz band (38.17% bandwidth) with maximum insertion loss (IL) 1.66 for normal incidence both <italic...

Landslide is a typical geological disaster distributed in most countries worldwide. Due to long-term natural weathering and human engineering disturbances, the instability of landslides prone occur. Once monitoring disposal methods are implemented inappropriately, they can lead landslide hazards, seriously threatening safety people’s lives property. For long time, extensive research on has been conducted from various countries, providing crucial technical support for reducing incidence...

Recently, it has been demonstrated that control techniques based on sliding mode (SMC) are robust and their performances quite remarkable for applications to active/hybrid of seismic-excited linear, non-linear or hysteretic civil engineering structures. In this paper, methods further extended by introducing a compensator. The incorporation compensator provides (i) convenient way making trade-offs between efforts specific response quantities the structure through use linear quadratic optimal...

The long-term settlement of calcareous sand foundations caused by daily periodic fluctuations has become a significant geological hazard, but effective monitoring tools to capture the deformation profiles are still rarely reported. In this study, laboratory model test and an in situ were conducted. An optical frequency domain reflectometer (OFDR) with high spatial resolution (1 mm) accuracy (±10-6) was used record soil strain responses groundwater table varied loads. results indicated that...

Recently, H∞ and sliding mode control methods have been investigated for applications to active/hybrid of seismically excited structures. Numerical simulation results indicate that both are quite promising civil engineering applications. In the present paper, shaking table experimental tests were conducted verify continuous methods. The test structure used was three-story 1/4-scaled building model, equipped with an active tendon system, which extensively at State University New York,...

An active mass driver has been designed for installation on the upper observation deck of 310 m Nanjing TV transmission tower in China order to reduce acceleration response under strong wind gusts. In this paper, linear quadratic Gaussian (LQG), H∞, and continuous sliding mode control (CSMC) strategies have applied system based feedbacks. Emphasis is placed practical applications LQG, CSMC controllers, including limitations actuator peak force stroke, limited number sensors, noise pollution....