地面物探技术在隧道掘进破碎带区段的应用

Application of high density resistivity method and transient electromagnetic method for Advanced Prediction in Tunnel

广佛环大太区间在隧道施工过程中出现多次掉块及局部地段沉降等现象,为查明掘进破碎带区上部的发育情况,采用高密度电阻率法和瞬变电磁法两种地面物探技术进行综合探测,结果表明:高密度电阻率法具有快速、高效等优点,能较好地反映出浅部的不良地质体;瞬变电磁法具有灵活、探测深度大等优点,对探测中深部的不良地质体有一定的效果。该组合物探技术由浅到深基本探明了隧道范围上方的地质变化情况,解释了引起隧道掉块及局部沉降的原因,为下一步的施工处理提供指导性意见。

During the tunnel construction in the Datai section,there were many falling blocks and settlements of local sections.In order to find out the geological conditions of the upper part of the excavation fracture zone,the ground geophysical exploration technology was used for detection.The combination of the high-density resistivity method and transient electromagnetic method shows that the high-density resistivity method has the advantages of fast and high efficiency and can better reflect the poor geological bodies in the shallow part.The Transient electromagnetic method has the advantages of flexibility and large detection depth,and it has specific effect on detecting medium and deep unfavorable geological bodies.The combined geophysical prospecting technology has proved the geological changes above the tunnel range from shallow to deep,explained the causes of the tunnel block falling and local settlement,and provided guiding opinions for the following construction treatment.