Shaking Table Tests of Embankment Models Reinforced with Geotextiles - Reinforced Soil Engineering: Advances in Research and Practice - page 382

were analyzed by using the finite-element method and compared with the
test results.
1 INTRODUCTION
Many soil structures such as earth dams, reclamation dikes, and farm roads have
been damaged by earthquakes. Surveys of damaged soil structures showed that
200 earth dams were damaged by the 1983 Nihon-Kai Chubu earthquake, while
1300 earth dams were damaged by the Hyogoken-Nambu earthquake.
Foundation ground and embankments are especially prone to heavy damage if
liquefaction occurs. Reinforcement of these soil structures is necessary to
improve earthquake resistance. Embankment models (earth dam, reclamation
dike) reinforced with (1) continuous fibers, (2) geogrids, and (3) foundation
improvement with cement were subjected to shaking table tests to determine their
effectiveness.
2 REINFORCEMENT WITH CONTINUOUS FIBERS
This section reviews shaking table tests that were conducted on embankments
constructed with loose sand and reinforced with continuous fibers to investigate
the safety of this method during earthquakes. The method uses continuous fibers
and covers the embankment surface with a mixture of continuous fibers and sand.
2.1 Mechanical Properties of Reinforced Sand
Prior to the shaking table test, the mechanical properties of sand reinforced with
continuous fibers were investigated. The tests used two types of sand: A and B. A
was used in the mechanical tests, and both A and B in the shaking table tests.
Table 1 and Fig. 1 show the physical characteristics of the two sand types. The
mechanical tests were drained triaxial compression and cyclic triaxial tests.
The fibers mixed with the sand were polyester, with characteristics as shown
in Table 2 . Both tests used 10-cm-diameter and 20-cm-high specimens. The
specimens were a compacted mixture of constant-weight ratio of fibers to sand.
Fibers were mixed in, at a ratio of 0.2% of the dry weight of the sand. The density
of specimens. r d , was 1.52 (t/m 3 ).
The effective reinforcement was about 1% axial strain, and the difference
between the principal stress of the unreinforced and reinforced sand increased as
shown in Fig. 2.