劇烈瓦斯爆炸隧道洞口致損機理

李志鵬; 吳順川

doi:10.13374/j.issn2095-9389.2018.12.005

劇烈瓦斯爆炸隧道洞口致損機理

doi: 10.13374/j.issn2095-9389.2018.12.005

李志鵬¹,
吳順川^1,2, ,

1) 北京科技大學土木與資源工程學院, 北京 100083
2) 昆明理工大學國土資源工程學院, 昆明 650093

詳細信息

中圖分類號: TU45
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出版歷程
- 收稿日期: 2018-06-25

Damage mechanism of tunnel portal subjected to severe gas explosion

LI Zhi-peng¹,
WU Shun-chuan^{1,2
, ,}

1) School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China
2) Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China

摘要

摘要: 為探究洛帶古鎮隧道瓦斯爆炸下洞口襯砌致損機理，對隧道內積聚瓦斯等效、量化研究，采用LS-DYNA建立與洞門幾何結構一致的流固耦合數值模型并驗證，以RHT模型模擬混凝土并修正參數，對爆炸過程中沖擊波的傳播特征及強度、洞門致損機理研究分析，并將模擬結果與實際情況對比.研究表明：爆炸沖擊波在隧道內無規則的反射效應使其強度劇增、流場復雜，局部位置有聚焦現象，隧道內高壓達1.2~2.4 MPa；傳播過程中，靠襯砌一側沖擊波運動速度較快，形態也由“球狀”變為“喇叭”狀；當以平面波形態傳至洞門時，拱頂沖擊波強度增加56%，達2.8 MPa，并在削竹式洞門周邊發生衍射；自隧道傳出后，強度逐漸降低，邊墻及底板處的沖擊波沿縱向徑直射出，拱部沖擊波向斜上方運動，形成“蘑菇云”.爆炸作用下，襯砌曲邊墻腳處完全破壞；爆心距7 m范圍內襯砌受損嚴重；7~15 m范圍內拱部幾乎未受損；洞門受損嚴重.缺少圍巖的約束作用，洞門拱頂Y向、拱腳X向位移分別達0.26和0.14 m，迎爆面、背爆面拉應力分別介于7.9~31.5 MPa、4.9~15.6 MPa，背爆面出現多個應力峰值，洞門主要為受拉致損.經對比，洞門損傷特征的數值模擬結果與現場實際情況基本一致，可為后續的襯砌災害處治提供依據.
- 瓦斯爆炸 /
- 隧道洞門 /
- 沖擊波傳播 /
- 動力響應 /
- 損傷機理
Abstract: To investigate the damage mechanism of tunnel portal subjected to gas explosion in the Luodaiguzhen tunnel, equivalent and quantitative studies were carried out on the accumulation of gases in the tunnel, and a fully coupled numerical model with dimensions that were consistent with the actual dimensions was established by LS-DYNA and verified. The RHT model was used to simulate the concrete, and some parameters were modified. The propagation traits and strength of the blast shock wave and the damage mechanism of the tunnel portal were studied. The studies show that the strength of the shock wave is significantly enhanced due to its numerous irregular reflection. This results in a complicated wave field. The wave aggregates in local regions, and the pressure in the tunnel is 1.2-2.4 MPa. The wave near the lining travels faster during propagation, and its shape changes from the spherical to horn. The strength of the wave in the vault of the tunnel portal is increased by 56% to reach 2.8 MPa, and diffraction occurs in the vicinity of tunnel portal. After the wave is propagated from the tunnel, its strength gradually decreases, and the wave, which originally moves along the sidewall and floor, continues to travel along the longitudinal direction. The shock wave along the arch moves upward and forms a "mushroom cloud". The corner of the sidewall is destroyed completely during the explosion, and the lining suffers serious damage within 7 m of detonation, and the arch is almost intact in the range of 7-15 m. The tunnel portal is also severely damage. Without the constraint of surrounding rock, the displacement of the vault in the Y and X directions of the portal is 0.26 and 0.14 m, respectively, and the tensile stresses that acted at the front and back surfaces of the portal are 7.9-31.5 MPa and 4.9-15.6 MPa, respectively, and multiple peak stresses occur on the back surface of the portal. The damage of the portal is mainly caused by the tensile stress. By comparison, the numerical simulation results of the damage characteristics of the tunnel portal basically agreed with the actual situations. Therefore, the results can provide useful references for the treatment of lining hazards.
- gas explosion /
- tunnel portal /
- propagation of shock wave /
- dynamic response /
- damage mechanism

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參考文獻(3)

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