370
11 Experimental and Numerical Study of UHPCC-FST Columns …
not specified due to the secrecy considerations) on 1/4 scaled CFST columns (diameters of 102, 127 and 152 mm) with the capping beams to simulate the scenario of car
bomb attack on bridge columns, and it was shown that the CFST bridge column has
the prominent blast-resistance capacity. Li et al. (2013) conducted the field explosion test on twelve CFST column specimens, in which the effect of explosive charge
weight (25–50 kg), standoff distance (3.5–5 m), axial compression ratio (7.6, 16
and 23%), concrete cubic compressive strength (37–68 MPa) and longitudinal reinforcement ratio (6.9, 8.3 and 9.9%) on the blast performance of CFST columns were
systematically studied. It was derived that, the blast resistance of CFST column
is enhanced with increasing the concrete strength and steel reinforcement ratio, as
well as decreasing the axial compression ratio. By performing the contact explosion
test on the concrete-filled double-skin steel tube (CFDST) columns (core concrete
compressive strength is 40 MPa, charge weights are 0.6 and 1 kg) with different
outer steel tube thickness (6, 7 and 8.5 mm), Li et al. (2018) derived that the blastresistance capacity of CFDST column increases with increasing the outer steel tube
thickness. Remennikov and Uy (2014) carried out the field contact and close-range
explosion tests (0.05 ≤ Z≤ 0.15 m/kg
1/3 ) on five square sectional CFST columns
with the core concrete compressive strength of 46 MPa, the damage and failure
of column specimens were recorded. Zhang et al. (2016) prepared twelve Ultrahigh performance concrete (UHPC) filled (double-skin) steel tube columns with the
compressive and flexural tensile strength of core UHPC averaging 170 MPa and
33.8 MPa, respectively. Then, an experimental study on above UHPC-FST columns
subjected to close-range explosion (the scaled standoff distances were 0.41, 0.46 and
0.58 m/kg
1/3 ) was performed, in which the sectional shape of outer tube (circular
and square), charge weight (17.5, 35 and 50 kg) and the axial load (0 and 1000 kN)
were considered. Besides, under the close-range explosion with two scaled standoff
distances of 0.19 and 0.14 m/kg
1/3 , Sun (2013) and Cui et al. (2015) experimentally studied the dynamic response of CFDST columns (core concrete compressive
strength of 45.8–55.2 MPa) as well as the overpressure distributions of blast wave
acted on the columns, respectively.
As for the analytical and numerical studies of the column under close-range explosion, Zhang et al. (2015a, b, c) numerically studied the dynamic responses of CFDST
columns subjected to close-range explosion based on the CONWEP codes embedded
in the finite element program LS-DYNA. However, Remennikov and Uy (2014)
pointed out that the CONWEP code is not suitable for most practical threats in near
field, and then they proposed a simplified engineering-level model for the near-field
blast impulse to predict the dynamic responses of structural members. Furthermore,
based on Arbitrary-Lagrangian-Eulerian element method in LS-DYNA, Ngo et al.
(2015) numerically reproduced the close-range explosion test on CFST specimens
conducted in Remennikov and Uy (2014). Moreover, the equivalent single degree of
freedom method has been widely used to predict the dynamic response of structural
members under the blast loadings (Li and Meng 2002).
11 Experimental and Numerical Study of UHPCC-FST Columns …
not specified due to the secrecy considerations) on 1/4 scaled CFST columns (diameters of 102, 127 and 152 mm) with the capping beams to simulate the scenario of car
bomb attack on bridge columns, and it was shown that the CFST bridge column has
the prominent blast-resistance capacity. Li et al. (2013) conducted the field explosion test on twelve CFST column specimens, in which the effect of explosive charge
weight (25–50 kg), standoff distance (3.5–5 m), axial compression ratio (7.6, 16
and 23%), concrete cubic compressive strength (37–68 MPa) and longitudinal reinforcement ratio (6.9, 8.3 and 9.9%) on the blast performance of CFST columns were
systematically studied. It was derived that, the blast resistance of CFST column
is enhanced with increasing the concrete strength and steel reinforcement ratio, as
well as decreasing the axial compression ratio. By performing the contact explosion
test on the concrete-filled double-skin steel tube (CFDST) columns (core concrete
compressive strength is 40 MPa, charge weights are 0.6 and 1 kg) with different
outer steel tube thickness (6, 7 and 8.5 mm), Li et al. (2018) derived that the blastresistance capacity of CFDST column increases with increasing the outer steel tube
thickness. Remennikov and Uy (2014) carried out the field contact and close-range
explosion tests (0.05 ≤ Z≤ 0.15 m/kg
1/3 ) on five square sectional CFST columns
with the core concrete compressive strength of 46 MPa, the damage and failure
of column specimens were recorded. Zhang et al. (2016) prepared twelve Ultrahigh performance concrete (UHPC) filled (double-skin) steel tube columns with the
compressive and flexural tensile strength of core UHPC averaging 170 MPa and
33.8 MPa, respectively. Then, an experimental study on above UHPC-FST columns
subjected to close-range explosion (the scaled standoff distances were 0.41, 0.46 and
0.58 m/kg
1/3 ) was performed, in which the sectional shape of outer tube (circular
and square), charge weight (17.5, 35 and 50 kg) and the axial load (0 and 1000 kN)
were considered. Besides, under the close-range explosion with two scaled standoff
distances of 0.19 and 0.14 m/kg
1/3 , Sun (2013) and Cui et al. (2015) experimentally studied the dynamic response of CFDST columns (core concrete compressive
strength of 45.8–55.2 MPa) as well as the overpressure distributions of blast wave
acted on the columns, respectively.
As for the analytical and numerical studies of the column under close-range explosion, Zhang et al. (2015a, b, c) numerically studied the dynamic responses of CFDST
columns subjected to close-range explosion based on the CONWEP codes embedded
in the finite element program LS-DYNA. However, Remennikov and Uy (2014)
pointed out that the CONWEP code is not suitable for most practical threats in near
field, and then they proposed a simplified engineering-level model for the near-field
blast impulse to predict the dynamic responses of structural members. Furthermore,
based on Arbitrary-Lagrangian-Eulerian element method in LS-DYNA, Ngo et al.
(2015) numerically reproduced the close-range explosion test on CFST specimens
conducted in Remennikov and Uy (2014). Moreover, the equivalent single degree of
freedom method has been widely used to predict the dynamic response of structural
members under the blast loadings (Li and Meng 2002).