冲击荷载作用下双层包裹式加筋土防护屏障力学特性研究

Mechanical Characterization of Double-Wrapped Reinforced Soil Protective Barrier Under Impact Loads

摘要:

针对传统包裹式加筋土防护屏障在爆炸冲击荷载作用下存在沿筋土作用面滑移的风险,提出了双层包裹式加筋土防护屏障,研究了爆炸冲击荷载作用下加筋土防护屏障力学特性。利用有限元软件对双层包裹式加筋土防护屏障抵抗爆炸冲击荷载的情况进行数值模拟,并对不同大小爆炸冲击荷载作用下,不同加筋形式的防护屏障进行了土压力和变形演化规律对比分析。结果表明:双层包裹式加筋土防护屏障比传统包裹式加筋土防护屏障具有更强的荷载缓冲效果,双层包裹式加筋土防护屏障相较于传统包裹式加筋土防护屏障迎爆面、背爆面的最大水平土压力分别减小12.2%、7.5%,防护屏障迎爆面与背爆面水平土压力沿墙高先增加后减小,在与爆源同等高度处土压力最大;双层包裹式加筋土防护屏障相较于传统包裹式加筋土防护屏障迎爆面、背爆面的最大水平位移分别减小6.4%、0.8%,在爆炸冲击荷载作用下,加筋土防护屏障迎爆面与背爆面水平位移沿墙高先增加后减小,最大位移发生在与爆源同等高度位置处,背爆面受到扰动较小;随着土工格栅竖向间距的增加,防护屏障的水平位移也逐渐增大。

Abstract:

Aiming at the risk of slippage along the reinforced soil action surface under blast impact loading of traditional wrapped reinforced soil protective barriers, a double-wrapped reinforced soil protective barrier is proposed. The mechanical properties of the reinforced soil protective barriers under blast impact loading were investigated. Numerical simulations were conducted for double-wrapped reinforced soil protective barriers against blast impact loads using finite element software. Moreover, under the action of different magnitudes of blast impact loads, comparative analyses were performed on the earth pressure and deformation evolution laws of protective barriers with different reinforcement forms. The results show that double-wrapped reinforced soil protective barriers provide greater load cushioning than traditional wrapped reinforced soil protective barriers. Compared with traditional wrapped reinforced soil protective barriers, the maximum horizontal earth pressure on the blast-facing surface and back-blast surface of double-wrapped reinforced soil protective barriers is reduced by 12.2% and 7.5%, respectively. For both the blast-facing and back-blast surfaces of the protective barrier, the horizontal earth pressure first increases and then decreases along the wall height, reaching the maximum at the same height as the explosion source. Compared with traditional wrapped reinforced soil protective barriers, the maximum horizontal displacement of the blast-facing surface and back-blast surface of double-wrapped reinforced soil protective barriers is reduced by 6.4% and 0.8%, respectively. Under blast impact loading, the horizontal displacement of the blast-facing and back-blast surfaces of reinforced soil protective barriers first increases and then decreases along the wall height, with the maximum displacement occurring at the same height as the explosion source, and the back-blast surface is less disturbed. As the vertical spacing of geogrids increases, the horizontal displacement of the protective barrier gradually increases.