【摘要】 在褶皱、断层和软弱围岩共同作用时,岩石掘进机施工将面临很大困难。直径3 m多的昆明上公山引水隧道展布于普渡河背斜东翼,岩石掘进机在4 km+340 m～439 m近100 m长洞段砂泥质板岩中施工遇缓倾逆断层,发生数次卡机事故。开挖旁侧支洞时岩石掘进机后护盾出现严重挤压变形,现场对护盾进行了局部修护。结合复杂地质条件下软弱围岩矿物成分、力学强度及其构造控制作用,分析了旁挖导致护盾由近似两向转为单轴受压状态,提出了围岩蠕变发生条件和护盾变形破坏机理。采用人工扩挖旁洞、钢拱架支撑和超前导洞等工程处理措施收到一定成效。为尽可能避开前面地质条件复杂段,从该段开始隧道线路进行了调直。已有数个工程教训促使对岩石掘进机的适用条件进行认真反思。更多还原

【Abstract】 Integrative action from folding,faulting and squeezing of weaken rocks constitutes great challenge to normal function of tunneling boring machine(TBM).As a case studyt,he Shanggongshan tunnel for water transfer with a diameter over 3 m,located at the eastern blank of the Puduhe fold,southwestern China,was encountered squeezing,TBM jamming and plastic deforming of shields.Between chainages 4 km+340 m–439 m at a depth of about 200 m,where the sandy and argillaceous slates play dominant roles,together with a gentle dipping of reversed fault,a TBM is seriously jammed several times.Extra-excavation in both sides made the back shield seriously plastically deformed.This paper presents the analysis of its complicated geological background from mineral contents to mechanical properties,together with compression state of the shield from binary to uniaxial as progressive trial excavating for release of the shield.The squeezing of rocks and shield failure occurred more severely in the upper and right part of the tunnel cross-section.Actual measures as manual excavation outside of the shield,steel frame supporting and advanced adit for prediction were adopted.Adjustment of the tunnel alignment was carried out after this section encountered of more faults ahead of the working face.Previous unsuccessful case examples have made us carefully consider the suitability of TBM in complicated geological conditions.更多还原