Tunnel construction procedure A cycle of steps

Answer:

Excavation and support of shallow buried and broken section of V grade surrounding rock of portalHole wayThe thin covering layer, poor geological conditions, when the depth of excavation to the arch line, first into the hole wall and the guide pipe shed, the open cut tunnel lining after the completion of the long pipe shed is overlapped on the Dong, to form a fixed end of pipe roof support, opening into the inner wall in the protection of pipe roof under the heading of the two side wall to stagger the footage before and after (5 ~ 10m). If there is a small spacing must also be set prestressed anchor.

The construction and tunnel portalWith the support from top to bottom layered excavation hole slopes, and Myeong Dong, and permanent and temporary outside waterproof and drainage should be first, make the surface smooth water, avoid surface water erosion on slope. Is necessary to take artificial slope repair, prevent overbreak, reduce disturbance to the adjacent area; excavation slope will be used in the design of the door, reducing exposure to rock weathering, support to follow, within the jurisdiction for high slopes, if not timely, can not guarantee the safety, and many of the human condition waste,The lining must check and recheck side wall foundation Myeongdong geologic condition and the bearing capacity of the foundation, to meet the design requirements, measurement lofting, frame formwork support, assembling reinforcement, inside and outside the template, the first wall arch integral casting lining concrete, mixing pump into the mold, insert type vibrator with attached type vibrator tamping compaction device.For the construction of portal portal with cut bamboo, also for cutting bamboo cut, plane mounted wooden formwork according to the slope, the slope angle and side end die die fixed into a whole.The waterproof layer and backfillingAfter the completion of open cut tunnel lining strength up to 50% can be removed outside the mold, with a waterproof layer, each layer of backfill should be symmetrical on both sides of the height difference is not greater than 30cm, not more than 50cm, after re stratified backfill to the vault, filled to the completion of a good surface aquifuge.

Tunnel construction process, the first branch is a temporary payment, two lining is a permanent support.1, the hole before the edge, the construction of the slope (including drainage, electricity, etc.);2, the construction of large pipe shed3, measurement positioning line;4, drilling, blasting;5, slag, playing anchor, steel, injection (including the initial spray and spray)6, ahead of the anchor (after the pipe section)7, measuring the line;