1 Introduction
The topography and geological conditions where the transmission line is located have a great impact on the construction cost and construction cost. When cooperating with technical and economic majors, it is often easy to ignore the proportion of topography and geology, or fail to provide accurate proportional division. The following is a detailed explanation of the definitions of various terrain and soil and stone classifications in transmission lines.
2 Definition of various terrains
1) Flat: refers to the area where the terrain is relatively flat and broad, and the ground is relatively dry.
2) Hill: refers to the gently undulating and continuous low hills and mounds on the land, and the terrain is undulating less than 50m within 1km of the horizontal distance.
3) Mountains: refers to the general mountains or ravines, etc., with a horizontal distance of less than 250m and undulating terrain of 50 to 150m.
4) High mountain: refers to the area where it is difficult for manpower and livestock to climb, the horizontal distance is less than 250m, and the terrain is undulating 150 250m.
5) Steep ridge: refers to the area where the terrain is very steep, the horizontal distance is less than 250m, and the terrain is undulating more than 250m.
6) Mire: refers to fields and areas where muddy water is often accumulated.
7) River network: refers to the area where rivers are frequent and rivers cross vertically and horizontally, affecting normal land transportation.
8) Desert: refers to a barren area where the ground is completely covered by sand, the vegetation is very scarce, the rain is scarce, the air is dry, the surface changes and moves under the action of wind, and the temperature difference between day and night is large.
3. Classification and definition of soil and stone
1) Ordinary soil: refers to planting soil, sand clay, loess and saline-alkali soil, etc., mainly excavated with shovels, shovels and hoes, and a little soil that can be excavated after loosening with a pickaxe.
2) Hard soil: refers to the hard and difficult to dig laterite, tabular clay, heavy soil, kaolin, must be dug loose with an iron pickaxe, hoe, part of the crowbar, and then with a shovel, shovel to dig out of the soil.
3) Loose sand stone: refers to the mixture of gravel, pebbles and soil, all kinds of unsolid conglomerate, shale, weathered rock, rock with many joints and cracks (not mined by blasting method), and soil that can only be excavated with tools such as pickaxes, crowbars, sledgehammers, wedges, etc.
4) Rock: refers to all kinds of rocks that cannot be excavated with general excavation tools, and must be excavated by drilling, blasting or partially chiseled with a pickaxe.
5) Muddy water: refers to the water around the pit is often accumulated, the soil of the pit is loose, such as silt and swamp, etc., due to water infiltration and infiltration into mud during excavation, easy to collapse, need to use retaining plate and appropriate amount of drainage to excavate the soil.
6) quicksand: refers to the soil quality is sandy or layered sandy, the sand layer has upwelling phenomenon and is easy to collapse in the excavation process, and the soil can be excavated only by draining and using retaining plate or precipitation by well point equipment during excavation.
7) Dry sand: refers to the soil quality of low water content of sand or layered sand, which does not need to be drained during excavation, but needs to be excavated by retaining plates.
8) Puddle: refers to the soil quality is relatively compact, the pit wall is not easy to collapse during excavation, but there is groundwater gushing out, and the excavation process needs to be constructed with mechanical drainage.