【摘要】 为探索隧道防排水体系与地下渗流场之间的关系,研制了施工及运营期矿山法隧道渗流模型试验系统,其整体尺寸为3 m(宽)×3 m(高)×2 m(厚),包括渗流模型箱、加固区模拟装置、排(涌)水量采集装置、移动式循环水箱装置和数据采集装置。该试验系统能够方便、准确地测试矿山法隧道施工及运营阶段的水压力、排(涌)水量和渗流场变化,并可根据试验需求对不同水头作用下的围岩、注浆圈、掌子面预注浆区域和初衬等进行配置和更换,最大限度地还原隧道及其周边渗流场状态。依托实际工程,采用该渗流模型试验系统和以控制渗透系数为基础的围岩-支护体系相似材料开展了不同注浆圈渗透系数下的渗流模型试验研究。结果表明:随着注浆圈渗透系数减小,渗流速度减慢,渗流时间大幅增加;运营期隧道二衬和注浆圈背后的特征点水压分布规律相似,注浆圈渗透系数越小其分担水压的效果越明显;对于非扰动开挖状态下隧道拱顶的特征点,开挖区靠近掌子面时其水压力值呈快速减小的趋势,但仍有动水压的作用,注浆圈渗透系数的改变对掌子面前方围岩中的渗流影响有限;对于非扰动开挖状态下隧道拱底的特征点,不同注浆圈渗透系数下,开挖区各测点的离散性较大,随注浆圈渗透系数增大,初衬背后的水压力值逐渐增加,而注浆圈背后的水压力值呈下降的趋势。更多还原

【Abstract】 In order to explore the relationship between the waterproof and drainage system of tunnel and the underground seepage field,a seepage model test system of mined tunnel for construction and operation period was developed,including a seepage model box,a simulationdevice of reinforced area,a collecting device of water discharge,a mobile circulating water tank and a data acquisition device.The length,height and width of model test system were 3m,3m and 2mrespectively.It was convenient and accurate to test the water pressure,water discharge and seepage field changes of mined tunnel during construction and operation period.For different test requirements,this system can be feasible to change and configure surrounding rock,grouting circle,pre-grouting area on tunnel face and initial lining under different water heads and the real state of tunnel as well as its surrounding seepage field should be restored as much as possible.Based on the actual engineering,the seepage model test system,along with the new type of simulation material of surrounding rock-support system in view of controlling permeability coefficient,was applied to carry out seepage model tests under different permeability coefficients of grouting circles.The results show that with the decrease of permeability coefficient of the grouting circle,the seepage velocity slows down but the seepage time increases dramatically.The water pressure distribution laws of characteristic points behind the secondary lining and the grouting circle are similar during the operation period.The smaller the permeability coefficient of the grouting circle is,the more obvious the effect of bearing water pressure can be.For characteristic points of the vault of tunnel under the condition of non-disturbed excavation,the water pressure decreases rapidly when the excavation area closes to the tunnel face,but there is the effect of dynamic water pressure.The change of permeability coefficient of grouting circle has limited effect on seepage in the surrounding rock in front of the tunnel face.For the characteristic points of the arch bottom of tunnel in the non-disturbed excavation,the dispersion of each measurement point is large under different permeability coefficients of grouting circles.With the increase of permeability coefficients of the grouting circle,the water pressure behind the initial lining gradually increases but the water pressure value behind the grouting circle is in a downward trend.更多还原