2. 1 main machines and tools: pointed spade, flat spade, hammer, trolley, ladder, pickaxe, crowbar, steel ruler, slope scale, string or 20 # lead wire, etc.
2.2 Operating conditions:
2.2. 1 before earthwork excavation, find out the obstacles such as underground pipelines, and clean and deal with the ground and underground obstacles in the construction area according to the requirements of the construction plan.
2.2.2 The location control line (pile) of the building (structure) or site, the standard horizontal pile and the grey line size of the foundation trench must be qualified through inspection, and the pre-inspection formalities shall be handled.
2.2.3 Clean and level the surface of the site, and do a good job in drainage gradient. In the construction area, temporary drainage ditch should be dug.
2.2.4 During construction at night, the working procedure should be arranged reasonably to prevent wrong excavation or overbreak. The construction site should be equipped with lighting facilities as required, and obvious signs should be set up in dangerous areas.
2.2.5 When excavating foundation pits (trenches) and pipe trenches below the groundwater level, measures should be taken to reduce the groundwater level according to local engineering geological data, generally to 50cm below the excavation bottom, and then excavation.
2.2.6 Be familiar with drawings and make technical disclosure.
3. 1 process flow:
Determine the excavation sequence and slope → cut out the contour line of the groove edge along the gray line → excavate in layers → trim the groove edge → clear the bottom.
3.2 Determination of slope:
3.2. 1 When excavating the foundation pit (trench) and pipe trench in the soil with natural humidity, when the digging depth does not exceed the following values, the slope shall not be left unsupported.
3.2. 1. 1 dense, medium dense sandy soil and gravel soil (with sandy soil as filler)-1.0m; ;
3.2. 1.2 hard plastic and plastic clay silt and silty clay-1.25m; ;
3.2. 1.3 hard plastic and plastic clay, macadam soil (filler is cohesive soil)-1.5m; ;
3.2. 1.4 Hard clay-2.0m.
3.2.2 When the depth exceeds the above specified depth and is within 5m, when the soil has natural humidity, uniform structure, good hydrogeological conditions and no groundwater, the unsupported foundation pit (groove) and pipe trench must be sloped. The maximum slope of the slope shall comply with the provisions of table 1- 1.
3.3 According to the foundation, soil and site excavation, reasonably determine the excavation sequence, and then excavate by sections and layers on average.
Table 1- 1 Slope of various soils
Slope (height: width)
There is no load at the top of the slope, but there is static load at the top of the slope.
1 medium dense sand1:1:1:1.251:1.50
2 Medium-dense gravelly soil (sand filling)1:0.751:1.001:1.25
3 hard plastic light loam1:0.671:0.751:1.00
4 Medium-dense gravelly soil (filled with cohesive soil)1:0.501:0.671:0.75
5 Hard plastic loam and clay1:0.331:0.501:0.67
6 Old loess1:0.101:0.251:0.33
7 Soft soil (after well point dewatering) 1: 1.00?
3.3. 1 When excavating various shallow foundations, if the slope is not laid, the contour line of the groove edge should be cut along the straight edge of the gray line first.
3.3.2 Excavation of various pits:
3.3.2. 1 shallow strip foundation. Generally, cohesive soil can be excavated in layers from top to bottom, and the depth of each layer should be 60cm. Starting from the excavation end, excavation shall be carried out step by step. Gravel soil should be loosened with picks first, and then excavated forward. The depth of each layer depends on the thickness of the turned soil, and each layer should be cleared and excavated, and then gradually excavated.
3.3.2.2 shallow ditch. It is basically the same as shallow strip foundation excavation, except that the ditch slope is not straight and uneven. According to the level of the portal frame plate, the elevation should return to the bottom of the ditch. When the excavation is close to the design elevation, return 50cm from the elevation of the ditch bottom below the portal frame plates at both ends as the reference point, stay and check the elevation of the ditch bottom with a ruler, and finally trim the ditch bottom.
When digging pits (ditches) and pipe trenches in 3.3.2.3, rough excavation should be carried out according to the slope specified in the construction plan, and then gradient lines should be made in layers according to the slope requirements, and a line should be made every 3rn or so, and the slope should be shoveled out based on this line. When digging a deep ditch, a dumping platform with a width of about 80 cm should be left in the middle of the ditch.
During the excavation of a large-scale line foundation pit in 3.3.2.4, three sides of the foundation pit are excavated at the same time, and the excavated earthwork is loaded into trolleys or dumpers and transported from the excavated surface to the spoil ground.
3.4 When excavating a foundation pit (trench) or pipe trench, when approaching the groundwater level, the excavation at the lowest elevation should be completed first, so as to carry out centralized drainage there. After excavation, when the excavation is within 50 cm from the bottom of the tank, the measuring and setting-out personnel should cooperate to copy out the plane line 50 cm from the bottom of the tank; Every 2 ~ 3m, from 20cm at the bottom of each channel, put the horizontal elevation of Xiao Mu Zhi Ding on the channel help. When digging to the elevation near the bottom of the tank, use a measured ruler or a 50cm standard ruler to level the Xiao Mu strut at any time to check the elevation at the bottom of the tank. Finally, use the stakes at both ends of the axis (center line) to pull through the line, check the size from the groove edge, determine the groove width standard, and trim the groove edge accordingly, and finally remove the earthwork at the bottom of the groove, trim the bottom and level it.
3.5 The vertical edge and slope of foundation pit (trough) shall be protected during excavation and exposure to prevent collapse, if necessary.
The stability of the slope and vertical edge should be ensured when the soil is abandoned at the edge of the excavation groove. When the soil quality is good, the earthwork (or materials) thrown to the groove edge should be 0.8m away from the groove (ditch) edge, and the height should not exceed l.5m Around the column base, wall base or one side of the fence, the pile of soil should not be too high.
3.6 When earthwork for foundation pit (trench) excavation is piled up at the site, good soil required for backfilling must be reserved, and the surplus earthwork should be transported to the spoil ground at one time to avoid secondary handling.
3.7 Earthwork excavation is generally unfavorable in rainy season. Otherwise the working face should not be too large. It should be done in stages, piece by piece.
When excavating foundation pit (ditch) or pipe trench in rainy season, attention should be paid to slope stability. If necessary, you can appropriately slow down the slope or set up support. At the same time, embankment or trench should be used around the pit (groove) to prevent the inflow of surface water. In the process of construction, we should strengthen the inspection of slope, support, earth embankment, etc.
3.8 Earthwork excavation should not be carried out in winter. If construction must be carried out in winter, the construction method should be carried out according to the winter construction plan.
When excavating earthwork by freezing method, the topsoil can be covered with heat preservation materials or plowed with harrows before freezing, and the ploughing depth should be determined according to the local climatic conditions, generally not less than 0.3m
When excavating a foundation pit (ditch) or pipe trench, the foundation soil under the foundation must be prevented from freezing. If the foundation pit (trench) is shut down for a long time after excavation, appropriate thickness of loose soil shall be reserved above the basement elevation, or covered with other thermal insulation materials, and the foundation shall not be frozen. When the foundation and foundation of adjacent buildings (structures) are exposed due to earthwork excavation, anti-freezing measures should be taken to prevent freezing injury.
4. 1 guarantee project:
4. 1. 1 The soil quality of column foundation, foundation pit, foundation trench and trench base must meet the design requirements, and disturbance is strictly prohibited.
4.2 See table 1-2 for allowable deviation items.
Table 1-2 Allowable deviation value of foundation pit and pipe trench outline dimensions
Inspection method of allowable deviation (mm) of the project
1.23 High-way slope is long and steep +0 -50 -0. It is not allowed to use theodolite, stay wire and ruler to check the level, or use slope scale to check.
6. 1 Overexcavation of basement: excavation of foundation pit (ditch) or pipe trench shall not exceed the elevation of basement. If there is over-excavation in some places, the treatment method should be approved by the design unit, and it is not allowed to treat it privately.
6.2 pile foundation excavation in soft soil area should prevent pile foundation displacement: when excavating foundation pit on dense pile groups, symmetrical excavation should be carried out after piling is completed for a period of time; When excavating a foundation pit (groove) near dense piles, measures to prevent the displacement of pile foundation should be determined in advance.
6.3 The foundation is not protected: the disturbance to the foundation should be reduced as much as possible after the foundation pit (groove) is excavated. If the foundation cannot be constructed in time, a soil layer with a thickness of 0.3m can be set aside above the elevation of the basement, and the foundation can be dug up.
6.4 The construction sequence is unreasonable; Earthwork excavation should start from the low-lying area, and be excavated in layers and sections in turn to form a certain slope to facilitate drainage.
6.5 Insufficient excavation size: the excavation width of the foundation pit (groove) or the bottom of the pipe trench, in addition to the structural width, should increase the working face width according to the construction needs. Such as the width of drainage facilities and supporting structures, should be considered before excavation.
6.6 The slope of foundation pit (ditch) or pipe trench is not straight and uneven, and the basement is uneven: inspection should be strengthened, and repair should be carried out while excavating, and acceptance should be made carefully.
This technical standard is applicable to the mechanical excavation of large-scale foundation pits (trenches), pipe trenches and large-scale leveling sites for industrial and civil buildings and structures.
2. 1 Main machines and tools:
2. 1. 1 Earthmoving machinery includes excavators, bulldozers, scrapers, dump trucks, etc.
2. 1.2 general machines include shovels (pointed heads and flat heads), trolleys, small white wires or 20 # lead wires and steel tape measures, and slope scale.
2.2 Operating conditions:
2.2. 1 Before earthwork excavation, the underground and ground obstacles in the construction area shall be cleaned and treated according to the requirements of the construction plan.
2.2.2 The dimensions of the positioning control line (pile), standard horizontal pile and slotted grey line at the location or site of the building or structure must be inspected; And complete the pre-inspection procedure.
2.2.3 During construction at night, there should be sufficient lighting facilities; Dangerous areas should be clearly marked, and the excavation sequence should be arranged reasonably to prevent wrong excavation or overbreak.
2.2.4 When excavating foundation pits and trenches with underground water level, measures should be taken to reduce the underground water level according to local engineering geological data. Generally, it should be lowered to 0.5m below the excavation face before excavation.
2.2.5 The roads, bridges and unloading facilities that the construction machinery passes through when entering the site shall be inspected in advance, and preparations for reinforcement or widening shall be made when necessary.
2.2.6 The selection of earth-moving machinery should be based on the terrain and operating conditions of the construction area, the type and thickness of soil, the total amount of works and the construction period, etc., so as to give full play to the efficiency of construction machinery and make a construction plan.
2.2.7 The layout of operation routes in the construction area shall be determined according to the scale, mechanical performance, transportation distance and topography of the project in the operation area.
2.2.8 In the parts where mechanical construction cannot be carried out, manual trimming of slope gradient and cleaning of trough bottom should be adopted.
2.2.9 Be familiar with drawings and make technical disclosure.
_
3. 1 process flow:
Determine the excavation sequence and slope → average excavation by sections and layers → trimming and bottom cleaning.
3.2 Determination of slope:
3.2. 1 When excavating the foundation pit (trench) and pipe trench in the soil with natural humidity, the slope shall not be left unsupported when the excavation depth does not exceed the following numerical values.
3.2. 1. 1 dense, medium dense sandy soil and gravelly soil (sand as filler)-1.0rn.
3.2. 1.2 hard plastic and plastic clayey silt and silty clay-1.25m.
3.2. 1.3 Hard plastic and plastic clay, crushed stone soil (filled with cohesive soil)? .5 meters.
3.2. 1.4 Hard clay-2.0m.
3.2.2 When the depth exceeds the specified depth and is within 5m, when the soil has natural humidity, uniform structure, good hydrogeological conditions and no groundwater, the unsupported foundation pit (trench) and pipe trench must be sloped. The maximum slope of the slope shall comply with the provisions of Table l-3.
Table 1-3 Slope of various soils
Slope (height: width)
There is no load at the top of the slope, static load at the top of the slope and dynamic load at the top of the slope.
1 medium dense sand1:1:1:1.251:1.50
2 Medium-dense gravelly soil (sand filling)1:0.751:1.001:1.25
3 hard plastic light loam1:0.671:0.751:1.00
4 Medium-dense gravelly soil (filled with cohesive soil)1:0.501:0.671:0.75
5 Hard plastic loam and clay1:0.331:0.501:0.67
6 Old loess1:0.101:0.251:0.33
7 Soft soil (after well point dewatering) 1: 1.00?
Note: When you have mature experience, you are not restricted by this table.
3.2.3 The slope gradient of temporary excavation used for a long time shall be determined according to the engineering geology and slope height, combined with the stable slope value of local similar soil. If the geological conditions are good and the soil (rock) is uniform, the slope gradient of the temporary excavation with the height within the range of 10m shall be determined according to Table 1-4:
Table of various soil excavation slopes 1-4
Classification slope of subgrade soil (height: width)
1 sandy soil (excluding fine sand and silt)1:1.25 ~1:1.
Hard1:0.75 ~1:1.00
Hard plastic1:1.0 ~1:1.25
Filling hard and hard plastic clay1:0.5 ~1:1.00
Filling sand1:1.00 ~1:1.50
Note: When you have mature experience, you are not restricted by this table.
3.2.4 When the excavation passes through different types of soil (rock) layers or the depth exceeds 10m, the slope can be made zigzag or stepped.
3.2.5 When the use of slope protection piles is restricted due to the adjacent buildings in urban excavation, the slope may not be put, but the construction scheme of slope protection piles is required.
3.3 When excavating a foundation pit (ditch) or pipe trench, the excavation sequence, route and depth shall be reasonably determined.
3.3. 1 When excavating a large foundation pit (trough) with a bulldozer, generally, the soil should be pushed from both ends or the top (longitudinally), pushed to the middle or the top, temporarily stacked, and then pushed away laterally from both sides of the foundation pit (trough).
3.3.2 When excavating a large foundation pit (trough) with a scraper, it should be excavated downwards in layers according to the longitudinal branches of the slope line, but the center line of each layer should be slightly higher than both sides to prevent water accumulation.
3.3.3 There are two construction methods for excavating foundation pit (ditch) or pipe trench with backhoe and dragline excavator.
3.3.3. 1 end excavation method: the excavator travels backwards to excavate from the end of the foundation pit (groove) or pipe trench. Dump trucks are arranged on both sides of the excavator to load soil.
3.3.3.2 lateral excavation method: the excavator moves along one side of the foundation pit (trench) or pipe trench, and the dump truck loads the soil on the other side.
3.3.4 When the excavator moves along the excavation edge, the width of the machine from the upper edge of the slope should not be less than 1/2 of the depth of the foundation pit (trench) or pipe trench. When the excavation depth exceeds 5m, it shall be determined according to the professional construction scheme.
3.4 Earthwork excavation shall be carried out in layers and sections from top to bottom. Make a certain slope at any time to facilitate drainage.
3.4.l During the excavation, the state of the groove wall and slope shall be checked at any time. When the depth is greater than 1.5m, the foundation pit (trench) or pipe trench should be prepared for collapse prevention according to the soil change.
3.4.2 The excavation of foundation pit (groove) and pipe trench shall not be lower than the design elevation. If the design basement elevation cannot be reached accurately, a layer of soil can be left above the design elevation without digging, and it can be dug manually after leveling.
Temporary soil layer: about 20cm for general scraper and bulldozer, and about 30cm for backhoe, front shovel and pull shovel.
3.4.3 Earthwork that can't be dug by mechanical construction should be dug at any time with the help of manpower, and the soil should be transported to the place dug by machinery with trolleys, so that the machinery can dig in time.
3.5 Help repair and bottom cleaning. At the edge of the tank 50cm away from the design elevation of the tank bottom, copy out the horizontal line, nail the Xiao Mu lip, and then manually dig out the temporary soil layer. At the same time, both ends of the axis (center line) are driven to pull through the line (with small wire or lead wire), and the size is checked from the groove edge to determine the groove width standard, so as to trim the groove edge. Finally, clear the earthwork at the bottom of the trough.
3.5. 1 After the tank bottom is repaired and leveled, quality inspection and acceptance shall be conducted.
3.5.2 When earthwork for foundation pit (trench) excavation is piled up in a conditional site, sufficient good soil shall be reserved for backfilling; Excess earthwork should be transported away at one time to avoid secondary handling.
3.6 rainy season and winter construction:
3.6. 1 Earthwork excavation should generally not be carried out in rainy season, otherwise the working face should not be too large and should be completed by stages.
3.6.2 During excavation of foundation pit (trench) or pipe trench in rainy season, attention should be paid to slope stability. When necessary, the slope gradient can be appropriately slowed down or supported. At the same time, embankment or trench should be used around the pit (groove) to prevent the inflow of surface water. Check the slope, support and earth embankment frequently, and handle the problems in time when found.
3.6.3 Earthwork excavation is not suitable for winter construction. If construction must be carried out in winter, the construction method should be carried out according to the winter construction plan.
3.6.4 When earthwork is excavated by freezing method, before freezing, the topsoil can be covered with thermal insulation materials or raked flat, and the ploughing depth should be determined according to local temperature conditions. Generally not less than 30cm.
3.6.5 When excavating a foundation pit (ditch) or pipe trench, the foundation soil must be prevented from freezing. Loose soil with appropriate thickness shall be reserved above the elevation of the basement. Or covered with other thermal insulation materials. When the foundation and foundation of adjacent buildings or structures are exposed due to earthwork excavation, anti-freezing measures should be taken to prevent freezing injury.
4. 1 guarantee project:
4. 1. 1 The foundation soil of column foundation, foundation pit, foundation trench and site must meet the design requirements, and disturbance is strictly prohibited.
4.2 See Table l-5 for allowable deviation items.
Table 1-5 Allowable deviation of earthwork excavation and site leveling
Test method for allowable deviation (mm) of serial number items
1.23 The slope surface elevation is long, wide and steep +0 -50 -0. It is not allowed to use theodolite, stay wire and ruler to check the level, or use slope scale to check.
5. 1 Used to locate standard piles, axis guide piles, standard leveling points, gantry plates, etc. When digging and transporting soil, it is not allowed to collide or rest on the gantry plate. And should often measure and check whether its plane position, horizontal elevation and slope meet the design requirements. Positioning standard piles and standard leveling points should also be retested regularly to check their correctness.
5.2 During earthwork excavation, settlement and deformation of adjacent buildings or structures, roads and pipelines shall be prevented. If necessary, we should consult with the design unit or the construction unit to take protective measures and observe the settlement or displacement during the construction.
5.3 If cultural relics or ancient tombs are found during the construction, they should be properly protected and reported to the local authorities in time for treatment before the construction can continue. If permanent survey stakes or long-term observation points set by geological and seismic departments are found, they should be protected. When earthwork construction is carried out in the area where pipelines and cables are laid on the ground or underground, the written consent of the relevant administrative departments shall be obtained in advance, and measures shall be taken in the construction process to prevent the pipeline from being damaged and causing major accidents.
6. 1 Overexcavation of basement: The excavation of foundation pit (trench) shall not exceed the elevation of basement. If there is over-excavation in some places, the treatment method should be approved by the design unit, and it is not allowed to treat it privately.
6.2 The basement is not protected: after the foundation pit (trench) is excavated, the disturbance to the foundation soil should be reduced as much as possible. If the foundation can't be constructed in time, 30cm soil layer can be reserved above the basement elevation, and no excavation is needed until the foundation is ready.
6.3 Unreasonable construction sequence: Earthwork excavation should be carried out in strict accordance with the construction sequence specified in the construction plan, and attention should be paid to the excavation from the lower part first, and it should be carried out in layers and sections in turn to form a certain slope to facilitate drainage.
6.4 Construction machinery sinking: The soil quality and groundwater level must be known during construction. Bulldozers and scrapers generally need to shovel soil with groundwater level above 0.5m; Excavators generally need to dig above the groundwater level of 0.8 meters to prevent the machinery from sinking under its own weight. The bench height excavated by the front shovel excavator shall not exceed 1.2 times of the maximum excavation height.
6.5 Insufficient excavation size and large slope: the excavation width and slope at the bottom of foundation pit (trench) or pipe trench should be increased according to the construction needs, such as the width required by drainage facilities and supporting structures, in addition to the structural size requirements.
6.6 During construction in rainy season, 30cm soil layer shall be reserved for the foundation trench and pit bottom, and concrete cushion shall be laid after digging to the design elevation.
This process standard should have the following quality records:
7. 1 engineering geological investigation report.
7.2 Engineering positioning measurement record Hao.
This technical standard is applicable to the quality inspection of the foundation and pit (trough) subsoil of buildings or structures.
2. 1 Materials and main machines and tools
2. 1. 1 sand: generally medium sand.
2. 1.2 Main machines and tools:
2. 1.2. 1 manual drilling: general steel drill, made of steel bars with a diameter of φ 22 ~ 25mm, with a 60-degree conical drill bit and a drill length of1.8 ~ 2.0m; 8 ~ 10 pound sledgehammer.
2.2.2.2 mechanical drill: portable penetrometer (required in Beijing area).
Others in 2.2.2.3: hemp rope or lead wire, ladder (stool), trolley, crowbar (for pulling steel brazing), steel tape measure.
2.2 Operating conditions:
2.2. 1 The foundation soil has been dug to the design elevation of the foundation pit (trough), the surface should be smooth, and the axis and the width and length of the pit (trough) all meet the requirements of the design drawings.
2.2.2 According to the design drawings, draw the drilling position layout. If there are no special provisions in the design, it can be implemented according to Table l-6.
2.2.3 During construction at night, there should be sufficient lighting facilities, and the drilling sequence should be arranged reasonably to prevent wrong drilling or missing drilling.
2.2.4 Draw a horizontal line of 30cm on the drill pipe in advance.
3. 1 process flow:
Put the bit line → put the bit in place, pull out the bit and fill the sand.
↓ ↓
Record the number of blows and check the hole depth.
3.2 Pay-off according to the drilling position of layout; Nail a small stake or sprinkle white ash on the hole.
3.3 drill in place
3.3. 1 Manual drilling: aim the drill tip at the hole position, with one person righting the drill pipe and the other standing on the operating bench, and knock the top of the drill pipe with a sledgehammer; The hammer lifting height is generally 50 ~ 70 CrN, and the solder is driven vertically into the soil layer.
3.3.2 Mechanical drilling: aim the tip of sounding rod at the hole position, then put the piercing hammer on the drill pipe, straighten the drill pipe, pull up the piercing hammer to make it fall freely, with the hammer distance of 50cm, and drive the sounding rod vertically into the soil layer.
3.4 Record the number of blows. When the drill pipe is driven into the soil 30cm, record the number of blows and the number of blows. If the drilling depth is not specified in the design, it is generally implemented according to Table l-6.
3.5 Pull out the drill pipe: tie the drill pipe with hemp rope or lead wire, leave a ring, insert a crowbar or iron pipe into the ring, and pull out the drill pipe by using the lever principle. Every time you pull out the lasso, move the lasso down for a while, and so on until it is completely pulled out.
3.6 Displacement: Move the drill pipe or sounder to the next hole position and continue drilling.
3.7 Sand filling: The drilled holes can only be filled with sand after being inspected by quality inspectors and related foreman. When filling sand, it can be tamped with wooden sticks or steel bars every 30cm. There are two forms of sand filling, one is to fill sand in time after each hole is punched or several holes are punched; The other is to fill the sand once a day after playing.
Drilling arrangement table 1-6
Groove width (cm), spacing (m) and depth (m)
Less than 80 central platoon 1.5 1.5
80 ~ 200 two rows staggered 1.5
More than 200 clubs 1.5 2.0
The quincunx type 1.5 ~ 2.0 1.5 is not shallower than the short side.
3.8 Record arrangement: number the drilling holes in sequence, and fill in the number of blows in the unified table. The handwriting should be clear, and the brazing personnel and technicians should sign it and file it.
3.9 Construction in Winter and Rain Period:
3.9. 1 foundation soil shall not be drilled after rain.
3.9.2 When the foundation soil is hammered in winter, the insulation material shall be hoisted every few holes, and the cover shall not be hung on a large area to avoid the foundation soil from freezing.
4. 1 guarantee project:
The drilling depth must meet the requirements, and the number of hammering records must be accurate, and fraud is not allowed.
4.2 Basic projects
4.2. 1 The drilling position is basically accurate and there is no leakage.
4.2.2 Borehole sand filling should be dense.
5. 1 The drilling probe shall be marked after completion, and the drilling shall be protected. Without the re-inspection by the quality inspector and the relevant foreman, it shall not be blocked or filled with sand.
6. 1 When it is impossible to run in, the foreman or relevant technicians shall be required to cancel drilling or move the drill pipe. You have to hit, fill in the number of hammers at will.
6.2 The location and arrangement of detection holes in the record are wrong:
6.2. 1 First, compare the boreholes on the borehole layout with those on the record sheet to see if there are any mistakes. Correct or make up for mistakes in time when they are found.
6.2.2 Use colored pencils or symbols to separate different drilling holes (blow times) on the record sheet.
6.2.3 On the borehole layout, indicate the position of the hole number that is too hard or too soft, and draw the size of the dry well or grave, so that designers, surveyors or relevant departments can analyze and deal with it when inspecting the trench.
This process standard should have the following quality records:
Engineering geological survey report.
This technology standard is applicable to artificial backfill soil such as foundation pit, foundation trench, indoor floor, pipe trench, outdoor fertilizer pond and apron in general industrial and civil buildings.