A load bearing structure including a first fixed net layer, a second fixed net layer and a non-linear structure in between. The first fixed net layer may include a first layer of flexible, drapable fabric and a fixing material that fixes the shape of the first layer of flexible, drapable fabric. The second fixed net layer may include a second layer of flexible, drapable fabric and a fixing material that fixes the shape of the second layer of flexible, drapable fabric. The non-linear reinforcing structure may be in communication with the first and second fixed net layers and may be configured to share with the first and second fixed net layers a load applied to the load bearing structure.

A method of assembling a wind turbine tower by stacking a plurality of annular sections made of concrete above each other. The main connections are performed between two adjacent annular sections, for withstanding loads induced by a rotor. The auxiliary connections are performed between two adjacent annular sections, for withstanding loads induced by an earthquake and loads induced by the wind on the wind turbine in absence of the rotor, but not necessarily loads induced by the rotor. The method is characterized in that the auxiliary connections between two adjacent annular sections are performed prior to stacking the following annular section.

The present disclosure provides a real-time identification method for a nonlinear characteristic of a model-free in-service seismic isolation/vibration reduction device. The method includes: dividing a structure of a seismic isolation/vibration reduction system into a plurality of substructures, and defining a substructure where the seismic isolation/vibration reduction device is located as a target substructure; and using a General Extended Kalman filter with unknown inputs (GEKF-UI) to identify a linear stiffness and a damping coefficient of the seismic isolation/vibration reduction device and a linear stiffness and a damping coefficient of the target substructure, in the case that an external excitation on the seismic isolation/vibration reduction device is small so that the seismic isolation/vibration reduction system is in a linear state.

A seismic wave damping system, and a corresponding method, includes elements, embedded within a host medium, the elements defining a seismic damping structure, and the elements being arranged to form a border of a protection zone. The seismic damping structure is configured to attenuate power of a seismic wave, traveling from a distal medium to the host medium, that is incident at the protection zone. The seismic damping structure is characterized by a resonance frequency. The system further includes an anti-resonance damping structure positioned within the protection zone and configured to dampen a residual wave propagating within the protection zone at the resonance frequency. Embodiment systems offer synergistic advantages because resonance frequencies of seismic wave damping structures may be predicted by calculation and an anti-resonance damping structure may be built to attenuate waves of primarily only specific resonance frequencies supported by the seismic wave damping structure.

The present disclosure is drawn to methods and systems for determining a seismic response of a man-made structure to a given input earthquake. Sensors are used to obtain vibration data for data collection locations from one or more floors of the man-made structure, which may be ambient vibration data or vibration data resulting from forced vibration or shock testing. The vibration data is used to determine modal characteristics for the man-made structure, including mode shapes, natural frequencies, and damping ratios. The mass, centre-of-mass, and moment of inertia is also determined for the floors of the man-made structure. The modal characteristics are then translated from the data collection locations to the centre-of-mass based on the structure of the floors. Then, a seismic response of the man-made structure to an input earthquake is determined using the translated modal characteristics and the mass and moment of inertia of the floors.

The present disclosure is drawn to methods and systems for determining a seismic response of a man-made structure to a given input earthquake. Sensors are used to obtain vibration data for data collection locations from one or more floors of the man-made structure, which may be ambient vibration data or vibration data resulting from forced vibration or shock testing. The vibration data is used to determine modal characteristics for the man-made structure, including mode shapes, natural frequencies, and damping ratios. The mass, centre-of-mass, and moment of inertia is also determined for the floors of the man-made structure. The modal characteristics are then translated from the data collection locations to the centre-of-mass based on the structure of the floors. Then, a seismic response of the man-made structure to an input earthquake is determined using the translated modal characteristics and the mass and moment of inertia of the floors.

A ground level platform upon which is secured a liquid storage tank, the platform providing a dampening frame, an upper plate, a lower plate and a plurality of ground cleats attaching to aligned lower tank brackets, each paired and aligned ground cleat and lower tank bracket attached by a torsion tightened threaded bolt, the ground level platform absorbing and deterring vibration from earthquakes from damaging the secured liquid storage tank.

A system for attenuating seismic forces includes a reactor pressure vessel containing nuclear fuel and a containment vessel that houses the reactor pressure vessel. Both the reactor pressure vessel and the containment vessel include a bottom head. Additionally, the system includes a base support to contact a support surface on which the containment vessel is positioned in a substantially vertical orientation. An attenuation device is located between the bottom head of the reactor pressure vessel and the bottom head of the containment vessel. Seismic forces that travel from the base support to the reactor pressure vessel via the containment vessel are attenuated by the attenuation device in a direction that is substantially lateral to the vertical orientation of the containment vessel.

A seismic wave damping structure can include a structural arrangement including at least one pair of elements, each angled with respect to a vertical and extending into the earth and toward a protection zone. The elements thus form a tapered aperture, the structural arrangement defining the protection zone at an upper portion of the aperture. Each element defines an inner volume and contains a medium resistant to passage of an anticipated seismic wave in earth having a wavelength at least one order of magnitude greater than a cross-sectional dimension of the inner volume of each of the elements. The medium is at least one of air, gas, water, and viscous fluid. The structural arrangement is configured to attenuate power from the anticipated seismic wave within the protection zone relative to power from the anticipated seismic wave external to the protection zone.

System, device, and method of reinforcement for raised-floors and for equipment thereon. A system includes a vertical support member to fixedly connect to a top-tier of a raised-floor and to a bottom-tier of the raised floor. The vertical support member includes an internal rod surrounded by an external pipe. The internal rod and the external pipe are connected via a top-side cap and a bottom-side cap. A modular-length slanted support member is further connected to the vertical support member. The slanted support member is fixedly connected to the bottom-tier of the raised floor, or to another, neighboring, vertical support member.