Centrifugal Model Tests of Balance Weight Retaining Walls under Translation Movement

Abstract

To find out the earth pressure characteristic of a shoulder balance weight retaining wall and backfills deformation, two groups of geotechnical centrifuge model tests are designed based on the highway road shoulder balance weight retaining wall under translation movement, the results show that: 1) earth pressure of upper wall is linear distribution and the down wall is two-segments linear distribution because of the unloading effect which produced by the equilibrator, the unloading effect area is about 1/3 height of the down wall. 2) the arch effect exists in the top of the upper wall backfills, and the compaction degree is high, the arcing effect is more obvious. 3) The soil surface settlement should have a certain correlation on arching effect which presents in the top of the upper wall, and the arching effect weakening or collapse will cause the soil surface settlement spurt. INTRODUCTION Balance weight retaining wall is one of the gravity retaining walls, compared with other gravity retaining wall, the center of gravity moved backward because of equilibrator, so it making foundation pressure tends to balance, and improve the height of retaining walls and enhance stability against overturning of the wall (ZHANG Jiaguo, 2004). But the wall back form is more complex, it exists mutual influence on upper and down wall of earth pressure, so the earth pressure of balance weight retaining wall is more complex than the other walls(ZHANG Jiaguo,2004; ZHOU Jing,1963). Currently, the calculation of balance weight retaining wall of earth pressure based on the classical Coulomb earth pressure theory, generally use the calculation method that assumed the wall form is polygonal-shape(1,2,7), and not consider the movement model effect to earth pressure. Many literatures showed that wall movement model has a great impact on the earth pressure distribution. An rigid retaining wall experiment was showed by Fang (Fang,1985), the wall was 1.04m high, had vertical wall back. He described the earth pressure which the wall had three movement modes, such as the translation mode (T), the rotate about base(RB)and rotate about top(RT), finally, the result showed that the movement modes has a great impact on the earth pressure distribution. Another retaining wall experiment by ZHOU (ZHOU Yingying,1990) showed that under T mode, the earth pressure distribution was a parabola form(the gravity center is lower), in RB mode, the earth pressure distribution also put out a parabola form, but in RT mode, 545 ICLEM 2014: System Planning, Supply Chain Management, and Safety © ASCE 2014