Encasement of the wooden logs

(Figure # 1) The continuous encasement of the wooden logs

ENCASEMENT OF THE WOODEN LOGS (EN: curbing support; DE: Geviertzimmerung; FR: boisage à cadres, soutenement par cadres; ES: entibado de cuadros; RU: венцовая крепь) is the encasement of the frame type for the vertical and inclined (more than 45 degrees) mine workings, the major structural part of which is the rows of the wooden logs (the rectangular frames), which are situated perpendicularly to the axis of the mine working. According to the structure and technology for the construction, they distinguish: the continuous (or of the log shell type), on the struts, and suspended encasements of the wooden logs.

The continuous encasement of the wooden logs (see the Figure # 1) is purposed for the support of the vertical and inclined mine workings, which have been penetrated within the rocks with the medium strength and stability. This encasement represents by itself the wooden log shell, the log rows of which are stacked tightly (in case of the traversing through the rocks, which are prone to the heaving, they preserve the gaps). They construct this encasement using the tiers from the bottom to the top. They start the mounting of this encasement with the installation of the supporting log rows (with the intervals of 2-8 metres), onto which they lay the ordinary log rows. They embed the ends of the wooden logs (fingers) along the short side of the supporting log row into the supporting kerfs within the walls of the mine working. Along the long side of the encasement, they install the vertical beams and buntons. They make one of the kerfs (guiding) of the larger size alternately at the each side of the mine working.

(Figure # 2) The upper encasement on the struts

The encasement of the wooden logs on the struts (see the Figure # 2) is used in case of the conducting the vertical and inclined mine workings through the strong stable rocks. This encasement comprises the log rows, between which they install the struts, which are connected with the log rows using the groove and tenon methods; for the greater rigidity, they join the struts together using the metallic staples. The size of the tier is 3-7 metres. The sequence for the performance of the works is the same, as for the continuous encasement of the wooden logs.

The suspended encasement of the wooden logs (see the Figure # 3) is used in case of the conducting of the vertical mine workings through the sufficiently stable rocks, which are permitting the exposure of up to 1.5 metres. This encasement comprises the log rows, between which there are installed the struts. They construct this encasement from the top down to the bottom, following the advancement of the stope (with the lag of 2-3 metres). They hang the log rows, starting from the supporting beams, with the help of the steel rods, which they join one to another using the hooks. The distance between the ordinary log rows is 0.7-1.5 metres, while the distance between the supporting log rows is 25-30 metres. They fixate the intervals between the log rows using the ties, which are made of the wooden boards or one-sided rough wooden boards, and they fill the voids behind the encasement with the rock.

(Figure # 3) The suspended encasement of the wooden logs

The encasement of the wooden logs is the traditional mining encasement (prevalently wooden), this encasement has got the most broad distribution in case of the development of the ore deposits. This encasement is also used for the support of the auxiliary shafts, of the exploratory shafts (with the short time of service, the depth is up to 150 metres), of the raises (winzes), and of the exploratory vertical mine workings within the non-flooded, sufficiently stable rocks.