The leading support is a significant link of the tunnel support of the coal mine,but in domestic it had not formed a unified system of research of leading support equipment in return airway.

Combined on high stress and big deformation entry,metal articulated single beam and cross-articulated beam were used with combination,it was analyzed from designed craft and result,and a good experience was raised for spreading metal articulated beam in forepoling of entry.

Starting from the engineering practice,this paper probes into the principles,applicable conditions and construction processes of several forepoling technologies,and introduces the forepoling technology for the tunneling works.

The application of large-pipe-shed in advanced support in tunnel construction;

In the light of the phenomenon such as flowing sand,and sand boil subjected from the flowing sand stratum,in the construction of artificial digging piles,the advanced support with rein- foreement and the chemical churning pile technology can be used to form the watertight curtain,thereby preventing successfully the loss of san.

According to the mechanical and deformational properties,technical measures,such as small-pilot-steel-pipe pre-support before excavation,CD-excavation method and field measuring at typical cross section after excavation are adopted to ensure the security of construction.

This paper introduces crafts and methods of construction,parameters and construction procedure,using design and construction of steel pipes and automatic anchor pole to pre-support,under the bad geology condition in the segment of the tunnel with sandwich.

Careful analysis and design were made for the reinforcement, the pre-support of the upper portal and the blasting based on the local geotechnical conditions.

Design of advance support system for use in coal faces

On the advance support against the collapse and its application Jinzi mountain tunnel

Particular measures such as consolidation of earth mass and support in advance have been taken before the commencement of excavation in order to keep the fault zone in a steady condition while tunneling.