Roadbed rock excavation construction half-excavation and half-fill excavation program has what

Half-excavation and half-fill section excavation according to the working surface, the use of transverse step blasting method, longitudinal step blasting method, as well as the slope of the glossy blasting program:

a, layered transverse step blasting method

Layered transverse step blasting program is suitable for excavation of a narrower place, and the requirements of the flying rock strict control of the lot.

b, layered longitudinal step blasting method

Layered longitudinal step blasting program is suitable for the terrain is more gentle, far from the highway, river section.

c, slope excavation

According to the design of the slope using surface blasting excavation, hole diameter d = 40mm, gun spacing a = 500mm, the thickness of the surface W = 600mm, the charge 0.20 ~ 0.30kg/m.

Side slopes should not be over-excavated. Excavation slope should be renovated from the excavation surface downward in sections, every downward excavation of 2~3m, it is appropriate to brush the newly excavated slope, and at the same time, remove the dangerous rocks and loose stones, to ensure that there are no loose rocks and dangerous rocks on the slope.

The under-excavated part must be chiseled away. Over-excavation part should be used inorganic binding material stabilized gravel or graded gravel filling and compacting, is strictly prohibited with fine-grained soil leveling. When there is groundwater on the bottom surface of roadbed, seepage ditch can be set up for drainage, and the width of seepage ditch should not be less than 10cm, and the cross slope should not be less than 0.6%. Soakaway should be backfilled with hard gravel.