Page 165 - 《爆炸与冲击》2026年第4期

第 46 卷 吴 昊，等： 落石冲击框架T梁式RC棚洞损伤破坏评估 第 4 期

of the finite element model were validated. Furthermore, the damage patterns and dynamic responses of the prototype shed
tunnel without cushion, with sand cushion, and with sand-EPE composite cushion were compared and analyzed. Finally, taking
the maximum penetration depth of the rockfall reaching the total thickness of the roof slab and cushion as the failure threshold
of the shed tunnel, the corresponding relationship between the rockfall mass and the critical impact velocity was established,
which enabled rapid assessment of protective performance of shed tunnel. It indicates that: (1) Under the impact of a 15 t
rockfall at velocities of 10 m/s and 25 m/s, the damage to the shed tunnel without cushion is primarily concentrated in the
impact area of the roof slab. On average, the use of sand cushion and sand-EPE composite cushion reduces the peak impact
force by 92.8% and 91.6%, respectively; (2) At impact velocity of 10 m/s, the sand-EPE composite cushion exhibits superior
buffering and energy dissipation performance compared to the sand cushion. However, with impact velocity increasing to
25 m/s, the EPE in the composite cushion is rapidly compacted, leading to a diminished protective effect. In this scenario, the
impact force and energy transferred to the roof slab with the composite cushion are 89.3% and 37.8% higher than those with
the sand cushion, respectively; (3) The critical impact velocity of rockfall corresponding to the failure damage of the shed
tunnel follows an exponential decay trend as the rockfall mass increases. The application of cushions can increase the critical
impact velocity by 52% to 155%, significantly improving the protective performance of the shed tunnel.
Keywords: framed RC shed tunnel; rockfall impact; damage and failure; sand cushion; sand-EPE composite cushion

山区边坡落石灾害严重威胁山区交通基础设施安全运维和人民生命财产安全。框架钢筋混凝土
（reinforced concrete, RC）棚洞作为一种有效的原位被动防护结构 [1-3] 得到广泛应用，其顶板结构形式主要
包括 T 梁密排式（图 1（a））和纵板式（图 1（b））。此外，实际工程中通常在棚洞顶板铺设砂垫层或砂-泡沫
材料复合垫层进一步提升棚洞的抗落石冲击性能 [4-5] 。落石质量较大（1～200 t） [6-7] 、速度较高（10～
[8]
42 m/s） ，易造成 RC 棚洞顶板的冲击贯穿破坏（图 1（c）），如汶川地震后新建的 40 余座山区道路棚/明洞
[9]
中超过 80% 的构筑物因遭受落石冲击而发生损伤破坏 。因此，开展落石冲击下 RC 棚洞的损伤破坏分
析对于棚洞防护性能评估和防护设计具有重要的研究价值和工程意义。

Rockfall
T-beam

(a) T-beam type (b) Slab type (c) Penetration failure
图 1 钢筋混凝土棚洞
Fig. 1 RC shed tunnel

国内外学者针对 RC 棚洞抗落石冲击性能开展了一系列试验研究。Kishi 等 [10] 开展了落石冲击铺设
砂垫层的预应力倒 L 型框架和完全刚性框架梁式 RC 棚洞的足尺试验研究，其中落石质量为 3～5 t，冲
击速度为 9.9～24.2 m/s，结果表明：填充补偿收缩砂浆进行锚固的完全刚性框架 RC 棚洞可更好地将冲
击荷载传递至下部结构，具有更优异的抗冲击性能。Zhao 等 [11] 开展了落石冲击铺设不同垫层（砂垫层、
砂-发泡聚苯乙烯（expandable polystyrene, EPS）复合垫层和砂-发泡聚乙烯泡沫（expandable polyethylene,
EPE）复合垫层）的框架 T 梁式 RC 棚洞上部结构的 1/2.5 缩尺模型试验，其中落石质量为 318～2 212 kg，
冲击速度为 4.4～12.5 m/s，得出：相比砂垫层和砂-EPS 复合垫层，砂-EPE 复合垫层具有更优异的抗落石

多次冲击缓冲耗能和耐久性能。Yu 等 [12] 为研究复合垫层中 EPE 布设位置对其缓冲性能的影响，开展
了 5.1 kg 落石以 3.1～7.7 m/s 速度冲击铺设砂垫层和砂-EPE 复合垫层的框架板式 RC 棚洞 1/5 缩尺模型

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