Works in winter conditions. Direct development of frozen ground

Development (without prior loosening) can be carried out by two methods - block and mechanical.

The block method of development is applicable for large areas and is based on the fact that the solidity of frozen soil is broken due to cutting it into blocks. With the help of attached equipment on a tractor - a bar engine, the soil is cut at mutually perpendicular penetrations into blocks with a width of 0.6 ... 1.0 m (Fig. 3.6.). With a small depth of freezing (up to 0.6 m), it suffices to make only longitudinal cuts.

Bar machines performing the cutting of cracks have one, two or three cut chains hung on tractors or trench excavators. Bar machines allow cutting slits of 1.2 ... 2.5 m depth in frozen ground. Steel teeth with a cutting edge made of durable alloy are used, which prolongs their service life, while
wear or abrasion allows you to quickly replace them. The distance between the bars is taken depending on the soil through 60 ... 100 cm. The development is carried out using backhoes with a large capacity bucket or a block of soil, the fiber is moved from the site to the dump by bulldozers or tractors.

The mechanical method is based on force, and more often in combination with a shock or vibration effect on an array of frozen soil. The method is implemented using ordinary earth moving and earthmoving machinery and machines with specially designed working bodies for winter conditions (Fig. 3.7.).

Fig. 3.6. Block soil development scheme:

a- cutting gaps barovym machine; b - the same, with extraction of blocks by a tractor; c - development of a ditch with extraction of blocks of frozen soil with the help of a crane; 1 - layer of frozen soil; 2 - cutting chains (bars); 3 - excavator; 4 - cracks in frozen ground; 5 - chopped blocks of soil; b - blocks moved from the site; 7 - crane parking; 8-vehicle; 9 - tick capture; 10 - construction crane; 11 - tractor

Conventional serial machines are used in the initial period of winter, when the depth of soil freezing is negligible. A forward and reverse shovel can develop the ground at a freezing depth of 0.25 ... 0.3 m; with a bucket with a capacity of more than 0.65 m3-0.4 m; dragline excavator - up to 0.15 m; bulldozers and scrapers are able to develop frozen ground to a depth of 15 cm.

For winter conditions, special equipment has been developed for single-bucket excavators - buckets with vibro-impact active teeth and buckets with a gripper-tong device. Energy costs for cutting soil is about 10 times more than spitting. The installation in the cutting edge of the excavator bucket of vibro-impact mechanisms, similar to the work of a jackhammer, bring good results. Due to excessive cutting effort, such single-bucket excavators can develop an array of frozen soil in layers. The process of loosening and excavation of the soil is the same.

Soil development is carried out with multi-bucket excavators specially designed for trenching in frozen soil. For this purpose, serves a special cutting tool in the form of tusks, teeth or crowns with inserts of solid metal, mounted on buckets. In fig. 5.40 shows the working body of a multi-bucket excavator with active teeth for the development of rocky and frozen soils.

Layering of soil can be done by a specialized earthmoving and milling machine that removes chips to a depth of 0.3 m and a width of 2.6 m. The movement of the developed frozen soil is carried out with dozer equipment, which is included in the machine kit.