Seismic Response of Unanchored Bodies

Abstract

This paper is concerned with the response of a rigid body subjected to base excitation. Using analytical and numerical methods of investigation, the results are presented in a series of graphs giving (1) the criteria for initiation of various modes (rest, slide, rock and slide-rock) of response and, using an ensemble of 75 real earthquake acceleration records, (2) the mean plus standard deviation of the distance of sliding relative to the base and (3) the probability of overturning during rocking. Based on the results in (3), two tables are prepared which give, corresponding to probability of overturning equal to 0.16 and 0.5, allowable peak base acceleration.

Building contents sliding demands in elastically responding structures

“…They first re-derived Newmark's 1965 formula, and expressed in term of maximum displacement rather than velocity as used by Newmark. After comparing with displacement from their previous work [15], they concluded that Newmark's formula can be used if an adjustment factor (a function of friction coefficient and base acceleration) was applied.…”

“…These include investigations into block sliding response to earthquake motions [13][14][15][16][17][18][19][20][21][22][23][24], derivation of formulations and criteria for rigid bodies sliding due to base excitation [21,[25][26][27], and in-field analyses of sliding rock blocks [28][29][30][31][32]. Also, many observations of contents sliding and falling off shelves have been obtained from the 1976 San Fernando, the 1989 Loma Prieta, the 1994 Northridge, and the recent Canterbury earthquakes [33][34][35][36].…”

Experimental and analytical studies on the response of freestanding laboratory equipment to earthquake shaking

“…Although this may succeed in reducing sliding displacements, it substantially amplifies accelerations. The problem of equipment sliding has been studied in the past at various scales by Shao and Tung [4], Lopez Garcia and Soong [5,6], and Hutchinson and Chaudhuri [7].…”

Sliding fragility of block‐type non‐structural components. Part 1: Unrestrained components

“…Many of them are free standing or unrestrained, either by choice or by necessity. The seismic response of this class of components is very complex in the sense that several response modes are possible and in that these response modes exhibits highly non-linear characteristics [2][3][4]. While several previous studies [5][6][7][8][9][10] have addressed primarily the rocking response and its related failure mode (overturning or toppling), assessment of sliding-related limit states has received much less attention.…”