多條隧道交會段施工監測回饋分析

FEEDBACK ANALYSIS ON STABILITY OF INTERSECTION AREA OF SEVEN TUNNELS BASED ON MONITORING AND CONSTRUCTION DATA

多條隧道交會段之力學行為係複雜之三向度問题,以三維數值分析程式FLAC3D針對其7條隧洞交會之實際工程案例,模擬其實際挖撐過程,並與佈置於交會段各處斷面監測結果進行比對,以瞭解隧道目前開挖圍岩穩定性,同時進一步預測隧道後續施工行為。分析結果顯示:案例隧道交會段施工互制影響範圍有限,目前隧道大體處於穩定狀態;後續洞台降挖及另一主隧道開挖,在及時支撐情況下,圍岩變形量增加有限,隧道安全應無問题,惟仍應持續進行監測,確實掌握隧道行為。

The complicated stress will occur in the intersection area of tunnels. Therefore, 3D numerical analysis program, FLAC3D, is adopted for feedback analysis of a case of an intersection area of seven tunnels. The analysis results indicate that tunnels shall be in stable condition because sphere of tunneling influence and loosen zone of rock mass are small. Monitoring and field visual inspection on tunnel conditions shall be maintained to monitor the behavior of tunnels during the progress of excavation.