Shaking table

Fig. 11. Schematic diagrams of the basic types of jig where represents the jigging action (a) Denver/Har2 and (b) Batac. (c) Schmatic of a shaking table,...

This is a response spectrum obtained during a test in a laboratory while exciting the shake table with ground movements as in the RRS. The test object is mounted on the shake table. The test object should respond normally during such movements. The test conditions (i.e. TRS) should closely overlap the required seismic conditions (i.e. RRS) of Figure 14.25. 

Now that it is possible to establish test facilities in a laboratory to simulate the time history of an earthquake seismic tests are conducted by creating the ground movements in the test object. Other methods, such as by analysis or by combined analysis and testing, are also available. Refer to IEEE 344 and lEC 60980 for more details. For this purpose a shake table, able to simulate the required seismic conditions (RRS) is developed on which the test object is mounted and its performance observed under the required shock conditions. Since it is not easy to create such conditions in a laboratory, there are only a few of these facilities available. The better equipped laboratories are in Japan, the USA, the UK, Greece, Germany, India and China. In India the Earthquake Engineering Department (EQD) of the University of Roorkee (UoR) is equipped with these facilities. 

The test object is mounted on the shake table and subjected to movements at the desired level and frequency in the horizontal and vertical directions simultaneously and its performance is critically observed, recorded and... 

Figure 14.24(a) Panels mounted on a shake table during seismic tests at UoR... 

Figure 14.24(b) Typical time history (RRS) of shake table movements during a laboratory test... 

Normally the user provides the nature of a probable earthquake in the form of RRS, i.e. acceleration characteristic curves, period versus spectral acceleration, such as those in Figure 14.18. The first objective is to generate a signal which should be able to produce a time history, on a shake table, whose response spectra match those of the RRS. 

Passive test The test object is mounted on the shake table and subjected to both horizontal (X and Pj movements or one cumulative orthogonal horizontal and one vertical ground movement simultaneously. Accelerometers are mounted on the shake table to measure its movements and also on the test object at its most vulnerable points. These points may be identified by the manufacturer or the user to monitor the behaviour of the object in such locations. 

Equipment axis X-A"at45° to the line of horizontal actuator of the shake table (position 3). 

Kumar, A. and Basu, S. Isolation iti a shake table system . Workshop Proceedings on Base Isolation, New Delhi, June, (1989). 

Into each of 27 Erlenmeyer flasks are placed 150 mg of Kendall s Compound F (hydrocortisone). The flasks and contents are then sterilized for 15 minutes at 15 pounds steam pressure (120 C). To each flask are then added 5.0 ml of ethanol. The 24-hour bacterial culture is then transferred asepticaliy and the resulting suspensions are Shaken on a shake table at 220 rpm and 28°C for 48 hours. The pH at the end of the shake period is 7.0. 

Figure 2.16 Idealized arrangements of particles on a shaking table a = smaller, higher-density particples b = high-density particles, large in size and low-density particles, small in size c = lesser, low-density particles.

Gravimetric separation systems. These include jigs, shaking tables, Humphrey-type spiral concentrators, and so on. 

Bulk sediment samples ( 30 kg) of till (n=63) and glaciofluvial sediments (n=7) were collected in C soil-horizon (>1 m depth) from hand-dug pits, natural bluffs, and man-made exposures. Samples underwent heavy mineral separation (SG >3.2 g/cm3) using a shaking table and heavy liquid separation. Heavy indicator minerals were visually identified and picked from the sand-sized fraction (0.25 - 2.00 mm). 

Results and Discussion Till samples (about 8 kg of material) were collected up- and down-ice from the deposit, over a total distance of about 20 km (Fig. 2). The samples were put through a shaking table (<2 mm) and gold grain counts were reported. Sieving and heavy liquid (S.G. 2.8-3.2 and >3.2) separation followed. The PCIMs were identified in the 0.25-0.5 mm fraction. 

Figure E8.3.1. View of the octanol-water container on a shake table.

Initially, it is necessary to select carefully the assay incubation time. With that aim, different batches of MIP particles (2.5 mg mL ) were incubated for between 0 and 18 h at room temperature in polypropylene tubes on a shaking table with 250 nmol L 1 of PAAP in the absence and in the presence of 166 pg mL 1 of penicillin G (in acetonitrile-water, 99 1), with 2 mL of a fluorescently labeled penicillin (PAAP) [36]. As shown in Fig. 5, binding to the CP was very low in comparison to that of the MIP and 7 h were required to achieve equilibria. 

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