The last time I saw him four years ago, he was watering his vegetables with only a bucket in his determination to resume farming. It was then that I saw first-hand how the Tohoku earthquake and tsunami in Japan had completely and mercilessly obliterated his local farming community.
Full-scale testing to destruction at E-Defense gauges their widespread risk to society and the efficacy of reinforcing them with retrofits. On January 17, a 6.
Damage exceeded expectations, tragically exposing structural vulnerabilities across various building types. The majority of the destruction occurred in older houses. Their heavy tiled roofs were a traditional precaution against frequent typhoons, but it made them precariously top heavy.
Many homes toppled due to insufficient cross bracing in their wooden post and beam frames. Lower stories gave way as they struggled to support the strain from above.
Column grids sheared en masse, due to insufficient reinforcement. Concrete and steel viaducts supporting bullet trains and other vital rail and road infrastructure were also badly damaged.
Sections of the Hanshin Expressway, a major elevated traffic artery, lay toppled on its side — an enduring image of the catastrophe. Elsewhere, side streets were blocked by debris. Gridlock hindered the desperate relief effort as fires raged about the city. In total, aroundproperties were ruined by the earthquake and ensuing fires, leavinghomeless.
Structures built afterwhen codes were overhauled, suffered less damage. However, some of the collapsed structures were engineered to meet those updated regulations and calculated to be safe. These surprising failures exposed an unsettling truth: They are, by necessity, abstract simulations.
While testing small-scale mock-ups can provide a relative gauge of real-world performance, their miniaturization can distort the true effects of full-scale forces. To remove all doubt, one would have to build a full-scale model and subject it a full-force earthquake simulation to confirm its seismic strength and expose any critical points of failure.
A testing rig of this scale might seem logistically impossible, let alone prohibitively costly.
But this is exactly what the Japanese government has constructed. The name might sound like a hi-tech military installation.
E-Defense is an engineering marvel in its own right — with awesome destructiveness comparable to the robotic mecha giants, who fight to safeguard Japanese cities from annihilation in popular manga and anime series.
Within an enormous warehouse, known as the Experiment Building, wooden houses, concrete offices, and all manner of structures weighing up to 1, tons, are placed atop a kinetic platform and violently shaken to see whether they withstand or collapse into a heap of rubble.
From a control room overlooking the test floor, computers coordinate a dancing array of pneumatic pistons hidden beneath the moving platform.
Acting in unison, they thrust the bymeter table in all directions, replaying the erratic gyrating choreography recorded by seismographs during real-life earthquakes, like the one in Kobe.
In preparation for testing, structures are built inside an adjacent hangar, hoisted over into the experimental warehouse by a gantry crane, and placed onto the table.
This live data is fed back to computers in the control room and recorded for later analysis. Devising a gigantic hydraulic mechanism that could not only control, but also sustain such powerful loads was a substantial engineering feat in its own right. The forces of a violently convulsing ,ton load necessitated securing the foundation of the table directly to the bedrock below.
The shake table is powered by hydraulics, like the tricked-out suspensions that jack lowrider cars up and down.
In a neighbouring shed, four immense 4,horsepower gas engines power the hydraulic pumps that pressurise the system. A towering bank of bright red metal accumulators regulates the flow of hydraulic fluid. From back in the control room, a computer translates the recorded movements of a seismic event into signals that instruct servo valves to open and close, to release the pressure into the twenty-four pistons that drive the table.
Displacement occurs in all three directions, so seismographs record ground motion along the X,Y, and Z axes. The 3D forces make structural behaviour more difficult to predict and prepare for. An unique feature of E-Defense is that it can faithfully replay any recorded earthquake in all three of its movement vectors.
Enormous pivoting hydraulic actuators thrust the table from side to side, as well as up and down. The giant pistons are aligned to move the table along each axis.THE DIVINE FEMININE.
The Eternal Feminine is our Guide - Goethe This book is a celebration of the Sacred Feminine, the feminine face of God as it has been . Japan raced to avert a nuclear meltdown today by flooding a nuclear reactor with seawater after Friday's massive earthquake left more than people dead and thousands more missing.
- During meditation, I saw the words, TODAY IS THE RED STAR DAY! From previous mediations, you can see below in that I saw three stars. New Real-Time Tsunami Early Warning System Calculates Size and Distance Using Underwater Sound Waves. Acoustic waves that radiate from an earthquake can travel much faster than the tsunami .
We all piled into his van, and as we drove through town, I solemnly noticed a highway overpass with a line that marked where the water level had reached during the tsunami. Essay # 1. Introduction to Earthquake: An earthquake is a major demonstration of the power of the tectonic forces caused by endogenetic thermal conditions of the interior of the earth.