From the construction point of view, it can be classified according to what properties of the soil 5

According to the classification method of the "Code for the Design of Building Foundations", the rock and soil as the foundation of the building can be divided into rock, gravel soil, sand, silt, cohesive soil and artificial fill.

From the classification of rock and soil, there are different aspects and standards, the main classification is the classification of genesis, as well as according to the degree of hardness, according to the degree of integrity, according to the degree of weathering, according to the type of rock mass structure, according to the quality index of the rock mass, and according to the basic quality level of the rock mass to classify.

From the point of view of the classification of excavated rock and soil, the main category is a kind of soil can also be said to be soft soil, this kind of soil is also called sand, silt, alluvial sand layer, the degree of looseness can reach planting soil, silt or peat, the firmness coefficient can reach about it, the average bulk density is between, and the method of excavation can be excavated with shovels, hoes, etc.

For the second type of soil is also called ordinary soil, this kind of soil is silty clay, can also be moist loess, sand, sand, silt mixed with gravel or pebble planting soil or fill, the firmness coefficient is between, the average bulk density is between, the method of excavation can be excavated with a shovel and hoe, and less use a pickaxe to loosen the treatment.

Three types of soil is hard soil, this kind of soil is soft and medium dense clay, heavy silty clay, gravel soil, dry loess, loess containing gravel pebbles, silty clay, compacted fill, the solidity coefficient is between, the average bulk density is between, the method of excavation is mainly with a pickaxe, rarely with a shovel, hoe and other ways to excavate, for part of the use of crowbar to excavate.

The above content reference: Encyclopedia - Geotechnical.

Encyclopedia - Code for design of building foundations

From the construction point of view, it can be classified according to the hardness of the soil.

The engineering geological classification of soil refers to the division of soil and rock into eight categories according to the hardness of soil and rock and the difficulty of construction and excavation in building construction, which are soft soil, ordinary soil, hard soil, gravel and hard soil, soft stone, sub-hard stone, solid stone, and extra-hard stone.

Basic features: 1. Soil, like rock, is a product of natural history. The nature of soil is determined by its geological origin, formation time, place, environment, and mode, as well as the conditions of metagenetic evolution and current production. Such as the formation of loess in arid areas, moist and hot.

The laterite formed in the area and the silt formed in the still water area are completely different in nature.

2. Soil is a system composed of solid, liquid and gas phases. The solid phase is the main component of soil and is called the skeleton of soil. The pores between the soil particles can be filled with liquids or gases.

In the engineering classification of rock and soil, according to the classification method of the Code for Design of Building Foundation, the rock and soil as a building foundation can be divided into rock, gravel soil, sand, silt, cohesive soil and artificial fill.

According to the difficulty of earthwork excavation, the soil and rock are divided into eight categories, of which 1-4 types can be excavated by machinery and manually.

A type of soil: soft soil, mainly including sandy soil, silt, planting soil, silt, etc., solid coefficient.

Class II soil: ordinary soil, mainly including silty clay, moist loess, planting soil, fill, etc., with a solid coefficient.

Three types of soil: hard soil, mainly including compacted fill, gravel soil, dry loess, etc., solid coefficient.

Four types of soil: gravel and hard soil mainly include hard and dense cohesive soil or loess, medium compact clay soil or loess containing gravel pebbles, etc., with a solidity coefficient.

Five types of soil: soft stone Solidity coefficient Excavate with pickaxes and crowbars, and partially blast.

Six types of soil: sub-hard stone, solid coefficient, excavated with blasting, part of the wind pick.

Seven types of soil: solid stone with a solid coefficient of 10-18 excavated by blasting.

Eight types of soil: extra-strong stone with a solid coefficient of 18-25 excavated by blasting.

According to the "Engineering Classification Standard for Soil", soil is divided into macro-grained soil, coarse-grained soil, and fine-grained soil according to the relative content of different particle groups, which is the basic classification of soil.

According to the Code for Geotechnical Investigation, soil is divided into residual soil, slope soil, flood soil, impact soil, siltation soil, ice soil, aeolian soil, etc.

According to the particle size and plasticity index, soil is divided into gravel soil, silt soil, sandy soil, and cohesive soil.

earthworks on the foundation.

In terms of method selection, it is classified according to the five engineering properties of rock and soil, which are:

1. Internal friction angle.

2. Soil shear strength.

3. The natural moisture content of soil.

4. The dry density of the soil.

5. Looseness of soil.

According to the composition of the soil, it can be divided into cohesive soil, powder town or soil, gravel soil, silt soil, etc. According to the state of the soil, it can be divided into undisturbed soil, disturbed soil, and humus soil.

Degree of hardness.

1. A type of soil (loose soil).

2. Class II soil (ordinary soil).

3. Three types of soil (hard soil).

4. Four types of soil (gravel and hard soil).

5. Five types of soil (soft soil).

6. Six types of soil (sub-hard stone).

7. Seven types of soil (hard stone).

8. Eight types of soil (extra hard stone).

In the method selection of foundation earthwork, according to the five engineering properties of rock and soil, they are classified, namely:

1. Internal friction angle.

2. Soil shear strength.

3. The natural moisture content of soil.

4. The dry density of the soil.

5. Looseness of soil.

According to the composition of the soil, it can be divided into cohesive soil, silt, gravel, silt soil, etc. According to the state of the soil, it can be divided into undisturbed soil, disturbed soil, and humus soil.

It is conducive to the selection of the correct method for studying the properties of rock and soil, to make a reasonable evaluation of rock and soil, to unify understanding and exchange experience.

A type of soil: soft soil sandy soil; silt; alluvial sand layer; loose planting soil; Silt (peat).

2. Class II soil (ordinary soil).silty clay; moist loess; sand sanded with gravel and pebbles; silt mixed cobblestone (crushed) stone; planting soil; Fill the soil.

3. Three types of soil (hard soil).soft and medium-dense clay; heavy silty clay; gravelly soil; dry loess, loess containing crushed (pebble) stones; silty clay, compacted fill.

4) Four types of soldiers: gravel and hard soil. hard and dense clayey or loess; moderately dense clayey or loess containing pebbles, gravel; coarse pebbles; natural graded sand and gravel; Soft marl.

5) Five types of soil: soft stone. hard clay; medium-dense shale, marl, chalk; Conglomerates that are not tightly cemented: soft lime and shell limestone.

6. Six types of soil (sub-hard stone).mudstone, sandstone, conglomerate; solid shale, marl, dense limestone; Weathered granite, gneiss and syenite.

7) Seven types of scholars: solid stones. Marbled; Diabase; Porphyrite; coarse and medium-grained granite, solid dolomite, sandstone, conglomerate, gneiss, limestone; lightly weathered andesite; Basalt.

8. Eight types of soil (extra hard stone).Andesite; Basalt. granitic gneiss; Solid fine-grained granite, diorite, quartzite, gabbro, diabase, porphyry, amphibole.

According to the difficulty of earthwork excavation, the soil and rock can be divided into eight categories, so as to select the construction method and determine the amount of labor, and provide a basis for calculating labor, machinery and engineering costs.

1. A type of soil: soft soil.

It mainly includes sand, silt, alluvial sand layer, loose planting soil, silt (peat), etc., and the solidity coefficient is to use shovels and hoes to excavate, and a little with footsteps.

2. Class II soil (ordinary soil).

Mainly consists of silty clay; moist loess; sand sanded with gravel and pebbles; silt mixed cobblestone (crushed) stone; Planting soil, filling soil, etc., the solidity coefficient is, digging with a shovel and hoe, and a little loosening with a pickaxe.

3. Three types of soil (hard soil).

Mainly includes soft and medium-dense clays; heavy silty clay, gravel soil; dry loess, loess containing gravel pebbles, silty clay; The compacted fill, etc., the solidity coefficient is, mainly with a pickaxe, a little with a shovel, hoe digging, and some with a crowbar.

4. Four types of soil (gravel and hard soil).

It mainly includes hard and dense clayey soil or loess; moderately dense clayey or loess with gravel pebbles; coarse pebbles; natural graded sand and gravel; Soft marl, etc., the solidity coefficient is that the whole is excavated with a pickaxe and crowbar, then with a shovel, and partly with a wedge and sledgehammer.

5) Five types of soil: soft stone.

Mainly consists of hard clay soils; medium-dense shale, marl, chalk; conglomerates that are not tightly cemented; Soft lime and shell limestone, etc., the solidity coefficient is, excavated with a pickaxe or crowbar, sledgehammer, and some use blasting methods.

6. Six types of soil (sub-hard stone).

It mainly includes mudstone, sandstone, conglomerate; solid shale, marl, dense limestone; Weathered granite, gneiss and syenite, etc., the solidity coefficient is, excavated by blasting method, and partly with a wind pick.

7. Seven types of soil (hard stone).

Mainly includes marble; Diabase; Porphyrite; coarse and medium-grained granite; solid dolomite, sandstone, conglomerate, gneiss, limestone; lightly weathered andesite; Basalt, etc., the solidity coefficient is, and the blasting method is used to excavate.

8. Eight types of soil (extra hard stone).

Mainly includes andesite; Basalt. granitic gneiss; Solid fine-grained granite, diorite, quartzite, gabbro, diabase, porphyry, amphibole, etc., with a solidity coefficient of more than that, are excavated by blasting method.

There are five categories of rock and soil.

Geotechnical is a general term for any kind of rock and soil that makes up the earth's crust from the perspective of engineering and construction.

Rock and soil can be subdivided into five categories: hard (hard rock), sub-hard (soft rock), weakly connected, loose and unconnected, and with special composition, structure, state and properties.

In China, it is customary to refer to the first two categories as rocks and the last three as soils, collectively referred to as "rock and soil".

In earthworks, the soil is divided into eight categories according to the difficulty of soil excavation.

The way to control quicksand must be to reduce the hydrodynamic pressure.

According to the "Code for the Design of Building Foundation Foundation", the engineering classification of Zen soil is carried out, and the sand is ().

a.Soil with a particle size greater than 2 mm and 50 by total weight Soil with a particle size greater than 50 by full weight.

b.The particle size is greater than 2mm, the particle content is 50 by the full weight, and the particle size is greater than the particle content of 50 by the full weight.

c.The particle size is greater than 50 of the total weight of the soil, and the particle size is greater than 50 of the total weight.

d.The particle content of particles with a particle size greater than 2 mm is 50 of the total weight

Correct answer: 50 of the total weight of the particle size of the particle size greater than 2 mm, and 50 of the total weight of the soil with the particle size greater than 50 of the total weight.

Answers]: a, c, e

2021 2020 Edition Textbook p81

This question mainly examines the engineering classification of rock and soil, according to the difficulty of earthwork excavation, soil and rock can be divided into eight categories, including: a type of soil - soft soil;The second type of soil - ordinary soil;Three types of soil - hard soil;Four types of soil - gravel and solid soil;Five types of soil - soft stone;Six types of soil - sub-solid stones;Seven types of soil - solid stone;Eight types of soil - extra strong stone.

Among them, ordinary soil mainly includes: silty clay, moist loess, sand, sand, silt mixed with eggs (crushed) stones, planting soil, fill soil, etc.;The solidity coefficient is that digging with a shovel and hoe, and a little loosening with a pickaxe is stupid.

Answers]: a, c, e

This question assesses Qi Wei's engineering classification of geotechnicals. According to the difficulty of earthwork excavation, soil and rock can be divided into eight categories, including: a type of soil - soft soil;The second type of soil - Pucha Tsai Song Tong soil;Three types of soil - hard soil;Four types of soil - Xuzheng gravel solid soil;Five types of soil - soft stone;Six types of soil - sub-solid stones;Seven types of soil - solid stone;Eight types of soil - extra strong stone.

Among them, ordinary soil mainly includes: silty clay, moist loess, sand sanded with gravel and pebbles, silt mixed with pebbles (crushed) stones, planting soil, fill soil, etc.;The solidity coefficient is 0 6 0 8, excavated with a shovel and hoe, and a little loosened with a pickaxe.