盾构机双滚刀在复合地层中破岩机理

Breaking Rock Mechanism of Shield Machine with Double Hobs in Composite Stratum

针对华南地区广泛存在的复合地层地质条件,着重研究了盾构机双滚刀在该地层中的破岩机理。研究了在复合地层中双滚刀的最优刀间距以及不同岩层之间夹角对破岩的影响。结果表明:随着刀间距从88 mm增大到112 mm,滚刀受到平均法向力和平均滚动力均呈现先增大后减小再稍微增大的趋势,平均法向力与平均滚动力的比值在10~15;并且比能值先迅速减小,然后缓缓增大,刀间距/贯入度在25附近时比能值达到最小。双滚刀所受到的平均法向力与平均滚动力随着岩层夹角从15°增大到90°,呈现先减小后迅速增大的趋势;在45°左右夹角时,滚刀受到的力减小到最小。研究结果对复合地层中盾构机的破岩掘进有一定的指导意义。

The composite stratum exists widely in the southern area of China,so the rock breaking mechanism of the shield machine double hob cutting in rocks was studied emphatically.The optimal cutter spacing of double hobs and the influence of the included angle between different strata on rock breaking in composite strata were studied.The results show that as hob spacing increases from 88 mm to 112 mm,the average normal force and the average rolling resistance acting on the hob,firstly increases,then decreases and at last increases slightly again in magnitude.The ratios of average normal force to average rolling resistance are in the range of 10~15.The specific energy ratio,which is work done divided breaking rock volume,decreases rapidly firstly,and then slowly increases as hob space increases.When the ratio of hob space/penetration is around 25,the specific energy ratio reach the minimum.The average normal force and average rolling resistance acting on the double hobs firstly decreases and then increases rapidly in magnitude as the rock bedding angle increases from 15°to 90°.When the bedding angle is about 45°,these forces acting on the hob reach the minimum.The research results have an important guiding significance on the cutting rocks forward of double hobs of shield machine in the composite stratum.