398
12 Experimental Study on the Residual Seismic Resistance of UHPCC …
hexagonal, circular and corrugated section which can help to enhance the ductility
and local stability of the column, can efficiently confine the core concrete and prevent
the spalling damage of concrete under blast loading (Farahi et al. 2016; Nassirnia
et al. 2016; Fujikura et al. 2008).
In the existing studies of CFST member under blast loadings, Fouche and Bruneau
(2015) conducted a series of close-range explosion tests (0.12 ≤ Z≤0.27 m/kg
1/3 , Z
= a/W
1/3 is the scaled standoff distance, a is the standoff distance from the center
of the explosive to the surface of structure, W is the charge weight) on the concrete
filled double steel tube (CFDST) column. Three types of failure modes, such as local
buckling of outer steel tube, overall bending of the column, and failure of outer steel
tube, were observed. Li et al. (2019) also performed the close-range explosion tests
(0.1 ≤ Z≤0.18 m/kg
1/3 ) on four 1/3 scaled CFDST columns, in which the influences
of burst height and TNT charge weight on the blast resistance of the specimens were
analyzed. The main failure mode of CFDST column under the near-field explosion
was the local damage with slight overall deformation, and both the area and depth
of the crater increased with increasing the charge weight. Li et al. (2018) carried out
the close-in range explosion tests (0.05 ≤ Z≤0.06 m/kg
1/3 ) on the CFDST column,
and the effects of TNT charge weight and the outer steel tube thickness on the blast
resistance of CFDST column were investigated. It demonstrated that the CFDST
column exhibited localized damage under close-in range explosion, and there was
no occurrence of overall response. Remennikov and Uy (2014) conducted the field
contact and close-in range (0.12 ≤ Z≤0.15 m/kg
1/3 ) detonation test on five CFST
columns, and it was found that CFST column suffered the localized damage with
the rupture of the steel tube and the crushing of the inner core concrete. Zhang et al.
(2015a, b, 2016, 2017a, b) conducted a series of experimental and numerical studies
on the dynamic performance of ultra-high performance concrete filled double steel
tube (UHPC-FDST) column under blast loadings. Zhang et al. (2016) carried out the
near-field explosion test (0.4 ≤ Z≤0.5 m/kg
1/3 ) on six UHPC-FDST specimens with
square and circular sections, and the influences of sectional shape, scaled distance
of explosive, axial force on the structural failure mode of UHPC-FDST column
were examined. It was derived that the circular UHPC-FDST column could take
advantage of the high compressive strength and ductility of the core UHPC, which
could delay or prevent the buckling of the steel tubes under the near-field explosion.
In Wang et al. (2020a), the quantitative degradation of the axial load capacity of
the Ultra high performance cementitious composite filled steel tube (UHPCC-FST)
specimens as well as the dependence of column damage index on the charge weight
is experimentally determined.
Generally, the existing studies have the following limitations: (i) Ultra high performance cementitious composite (UHPCC) is a relatively new cement-based composite
with both prominent static and dynamic mechanical properties, and UHPCC filled
steel tube (UHPCC-FST) have been becoming the most prospective construction
bearing members for high-rise buildings and long-span bridges. However, the existing
work for the blast resistance of UHPCC-FST is limited; (ii) Considering the accessibility of bridge pier and the threat of terroristic car bombs, the most extreme contact
explosion scenario should be paid much more attention, while the existing studies
12 Experimental Study on the Residual Seismic Resistance of UHPCC …
hexagonal, circular and corrugated section which can help to enhance the ductility
and local stability of the column, can efficiently confine the core concrete and prevent
the spalling damage of concrete under blast loading (Farahi et al. 2016; Nassirnia
et al. 2016; Fujikura et al. 2008).
In the existing studies of CFST member under blast loadings, Fouche and Bruneau
(2015) conducted a series of close-range explosion tests (0.12 ≤ Z≤0.27 m/kg
1/3 , Z
= a/W
1/3 is the scaled standoff distance, a is the standoff distance from the center
of the explosive to the surface of structure, W is the charge weight) on the concrete
filled double steel tube (CFDST) column. Three types of failure modes, such as local
buckling of outer steel tube, overall bending of the column, and failure of outer steel
tube, were observed. Li et al. (2019) also performed the close-range explosion tests
(0.1 ≤ Z≤0.18 m/kg
1/3 ) on four 1/3 scaled CFDST columns, in which the influences
of burst height and TNT charge weight on the blast resistance of the specimens were
analyzed. The main failure mode of CFDST column under the near-field explosion
was the local damage with slight overall deformation, and both the area and depth
of the crater increased with increasing the charge weight. Li et al. (2018) carried out
the close-in range explosion tests (0.05 ≤ Z≤0.06 m/kg
1/3 ) on the CFDST column,
and the effects of TNT charge weight and the outer steel tube thickness on the blast
resistance of CFDST column were investigated. It demonstrated that the CFDST
column exhibited localized damage under close-in range explosion, and there was
no occurrence of overall response. Remennikov and Uy (2014) conducted the field
contact and close-in range (0.12 ≤ Z≤0.15 m/kg
1/3 ) detonation test on five CFST
columns, and it was found that CFST column suffered the localized damage with
the rupture of the steel tube and the crushing of the inner core concrete. Zhang et al.
(2015a, b, 2016, 2017a, b) conducted a series of experimental and numerical studies
on the dynamic performance of ultra-high performance concrete filled double steel
tube (UHPC-FDST) column under blast loadings. Zhang et al. (2016) carried out the
near-field explosion test (0.4 ≤ Z≤0.5 m/kg
1/3 ) on six UHPC-FDST specimens with
square and circular sections, and the influences of sectional shape, scaled distance
of explosive, axial force on the structural failure mode of UHPC-FDST column
were examined. It was derived that the circular UHPC-FDST column could take
advantage of the high compressive strength and ductility of the core UHPC, which
could delay or prevent the buckling of the steel tubes under the near-field explosion.
In Wang et al. (2020a), the quantitative degradation of the axial load capacity of
the Ultra high performance cementitious composite filled steel tube (UHPCC-FST)
specimens as well as the dependence of column damage index on the charge weight
is experimentally determined.
Generally, the existing studies have the following limitations: (i) Ultra high performance cementitious composite (UHPCC) is a relatively new cement-based composite
with both prominent static and dynamic mechanical properties, and UHPCC filled
steel tube (UHPCC-FST) have been becoming the most prospective construction
bearing members for high-rise buildings and long-span bridges. However, the existing
work for the blast resistance of UHPCC-FST is limited; (ii) Considering the accessibility of bridge pier and the threat of terroristic car bombs, the most extreme contact
explosion scenario should be paid much more attention, while the existing studies