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Research on Comprehensive Construction Technology for Retaining Structure of Special-shaped Deep Foundation Pit in Inclined Hard Rock
(1 Hebei Oriental College，Langfang 065001; 2 China Light Industry Construction Co., Ltd., Langfang 065001; 3 China Railway No. 3 Engineering Group Co. Ltd., Taiyuan 030001)
Abstract Aiming at the construction difficulties and hole deviation issuses of diaphragm retaining wall and bored pile in inclined hard rocks, the corresponding construction techniques of hole drilled by rotary drilling rig and trough constructed by piling machine, and bored hole drilled by down-the-hole drill rig + rotary drilling rig were proposed based on a theoretical and practical research, by taking the retaining structure construction of a deep foundation pit of a metro station as an example. The results show that: (1) in the construction of diaphragm retaining structure in hard rock, main holes are constructed with intervals by rotary drilling rig, and accessory holes are constructed by piling machine, which improves the construction speed of retaining structure; (2) It is difficult to construct the bored pile in the hard rock, and the quincunx bores are drilled by down-the-hole drill rig and then followed by rotary drilling, which greatly increases the construction speed; (3) by adjusting the perpendicularity of the rotary drilling rig and the down-the -hole drill rig, the inclination of troughs and holes is avoided, guaranteeing the perpen? dicularity in the inclined rock mass; (4) the technical parameters of rotary drilling rig should be optimized to guarantee the perpendicularity during the rotary drilling construction in inclined hard rocks.
Abstract：
Aiming at the construction difficulties and hole deviation issuses of diaphragm retaining wall and bored pile in inclined hard rocks, the corresponding construction techniques of hole drilled by rotary drilling rig and trough constructed by piling machine, and bored hole drilled by down-the-hole drill rig + rotary drilling rig were proposed based on a theoretical and practical research, by taking the retaining structure construction of a deep foundation pit of a metro station as an example. The results show that: (1) in the construction of diaphragm retaining structure in hard rock, main holes are constructed with intervals by rotary drilling rig, and accessory holes are constructed by piling machine, which improves the construction speed of retaining structure; (2) It is difficult to construct the bored pile in the hard rock, and the quincunx bores are drilled by down-the-hole drill rig and then followed by rotary drilling, which greatly increases the construction speed; (3) by adjusting the perpendicularity of the rotary drilling rig and the down-the -hole drill rig, the inclination of troughs and holes is avoided, guaranteeing the perpen? dicularity in the inclined rock mass; (4) the technical parameters of rotary drilling rig should be optimized to guarantee the perpendicularity during the rotary drilling construction in inclined hard rocks.
.Research on Comprehensive Construction Technology for Retaining Structure of Special-shaped Deep Foundation Pit in Inclined Hard Rock[J] MODERN TUNNELLING TECHNOLOGY, 2019,V56(1): 205-208
2019, Vol. 56 