小净距隧道爆破施工对邻近裂缝隧道动力响应的影响

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[ABSTRACT]Inorder to studythedynamic response lawof adjacent lining crack tunnelsduring blasting constructionof small clearance tunnels，numerical simulationmethodswereusedtostudythe efectof diferentdistribution positiosand depthsoflining cracks indiffrentlevelsofrockonblastingdynamicresponse.Theresultsshow thatthediffrentdistribution positions and depthsof lining cracks indiferent levelsofrock have no significantimpactonthevibration velocityresponseof the lining of existing tunnels.Butthere isacertain impact onthestressresponseof thelining of existing tuels. Theimpact isonlynearthecracksand varies withthedistribution positions，sizes，androck levels.Whenthere are cracks indiferentpositionsofthliningofexisting tunnels，thereisacertainamplificationefectonthetensilestressofthestructure.Theamplification efect is most significant when there arecracks inthe sidewallsfacing theexplosion.Atthe same position ofthe lining of the existing tunnel，thedeeper thecracks，thegreater thenearbyprincipal tensile stress.The higherthelevelof therock，the more significanttheamplificationeffectoftheprincipaltensile stress nearthecrack.When using vibration velocityas the safetycontrol benchmarkfor adjacent cracked tunnelsduringthe blasting construction process of newtunnels，thecontrol valueof vibration velocityatthecrack locationshouldbeappropriatelyreduced，andthedegree of reduction varies with the distribution position and depth of the crack.

[KEYWORDS]smal clear distance tunnel; blast； reconstruction and expansion； crack； dynamic response

0 引言

近年来，随着经济建设的快速发展，我国城市化建设不断向前推进，现有的道路交通运输能力已经无法满足日益增长的交通运输量[1]。（剩余8739字）