盾构机双滚刀在复合地层中破岩机理的

针对华南地区广泛存在的复合地层地质条件,本文着重研究了盾构机双滚刀在该地层中的破岩机理。主要包括两方面的研究,其一是研究在复合地层中双滚刀的最优刀间距；其二是不同岩层之间夹角的大小对破岩的影响。结果表明：(1)随着刀间距从88 mm增大到112 mm,滚刀所受到平均法向力和平均滚动力均呈现先增大后减小再增大的趋势,平均法向力与平均滚动力的比值在10~15之间；并且比能会先迅速减小,然后缓缓增大,刀间距/贯入度的值在25附近时比能值达到最小。(2)双滚刀所受到的平均法向力与平均滚动力,会随着岩层夹角从15°到90°的增大,呈现先减小后迅速增大的趋势；在45°左右夹角时,滚刀受到的力会减小到最小。这些结果对复合地层中盾构机的破岩掘进有一定的指导意义。

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

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 is studied emphatically. It is mainly included two parts in this paper, the first part is about the optimal hob spacing of double hobs in composite formations; the other is about the influences of the different rock bedding angles on rock breaking. The results are shown that: (1) As hob spacing is increased from 88mm to 112mm, the average normal force and the average rolling resistance acting on the hob, are firstly increased, then decreased and at last increased slightly again in magnitude; the ratios of average normal force to average rolling resistance are in the range 10 ~ 15; and the specific energy ratio, which is work done divided breaking rock volume, is decreased rapidly at firstly, and then slowly increased as hob space is increased. When the ratio of hob space/penetration is around 25, the specific energy ratio is reached the minimum. (2) The average normal force and average rolling resistance acting on the double hobs are firstly decreased and then increased rapidly in magnitude as the rock bedding angle is increased from 15° to 90°. When the bedding angle is about 45°, these forces acting on the hob are reached the minimum. These have an important guiding significance for the cutting rocks forward of double hobs of shield machine in the composite stratum.