Construction technology of the hottest hanging net

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Shotcrete anchor scheme construction technology

3.1 General requirements

(1) before the radioactive concrete is stopped on the slope, various preparatory tasks should be done according to the drawings or the instructions of the supervising engineer:

A. clean up the debris on the protective rock surface, broken pumice and loose rocks

b. wash the slope with high-pressure water and keep the rock surface at a certain humidity

(2) confirm the bolt hole position on the rock surface, stop drilling, and the hole depth and hole diameter should meet the requirements of the drawing. After drilling, the rock powder in the hole shall be blown clean

(3) install anchor bolts, and pour cement mortar into the borehole at the same time. Other data specified in the drawings and approved by the supervising engineer

(4) embed marks to control the thickness of radioactive concrete, and lay reinforcement and iron thistle. The size of the eye should be appropriate to the drawing. The reinforcement and geogrid should be connected with the anchor bolt safely, and the gap between them and the rock surface should be 30 mm, or as specified in the drawing

3.2 radioactive cement mortar

(1) slope shotcreting protection, the common ratio of cement mortar shall comply with the provisions of the drawings. If not specified in the drawing, the strength of mortar shall not be less than M10

(2) before shotcreting, trial shotcreting should be carried out to confirm the appropriate proportion and construction method. The results of trial shotcreting can be used for large-scale construction in front after being recognized by the supervising engineer

(3) for large-area shotcreting, an expansion joint with a width of 20 mm shall be set every 20 ~ 25m along the target

(4) the construction process of radioactive cement mortar can refer to the process requirements of radioactive concrete

3.3 radioactive coagulation, such as the national standard of the people's Republic of China gb5170 "methods for the verification of basic parameters of environmental experimental equipment for electrical and electronic products" (1) before construction, the construction process (dry and wet) of radioactive concrete and the common ratio of concrete should be confirmed, and the radioactive machines and tools used should be selected and reported to the supervising engineer for approval. Before radiating concrete, the predecessors should improve the trial spraying, adjust the rebound amount, confirm the common ratio of concrete and the construction operation method, and the large-scale construction can be carried out in front after the supervisor's work quantity recognition

(2) the common ratio of dissimilated materials of radial concrete should be suitable for the following provisions:

a. the component ratio of cement and aggregate should be 1:4 ~ 1:4.5

b. sand ratio 45% ~ 55%

c. the water cement ratio should be 0.40 ~ 0.45

d. the dosage of accelerator should be confirmed after experiment

(3) the joint design of radial concrete is confirmed by experiments

(4) dissimilated materials should be mixed and used at any time. When accelerator is not added, the storage time should not exceed 2H; When adding accelerator, the storage time should not exceed 20min

(5) during the transportation and storage of dissimilated materials, be careful not to mix with rain, dripping water, large stones and other debris, and be screened before loading into the radiation machine

(6) the radioactive concrete shall be stopped by sections and pieces from bottom to long. At the beginning of the lesson, you should first supply air, then start the machine, and then feed materials; At the end, the machine should be shut down after the spraying. The feeding to the radiation machine should be continuous and uniform. When the machine is in normal operation, there should be enough material in the hopper. The thickness of spraying layer shall be uniform and suitable for the thickness required by the drawing

(7) at the beginning of radiation, the interval from the nozzle to the sprayed slope should be reduced, and the radiation angle should be adjusted to ensure the compactness of concrete between Tribulus terrestris and the rock surface

(8) when radiating, the concrete should be kept roughly flat, moist and glossy, without dry spots or sliding flow

(not only reduces the pollution to the environment 9) after radiation, when using light Portland cement, the curing should be more than 10 days; When slag Portland cement or pozzolan Portland cement is used, the curing time shall not be less than 14 days, and the joint between the spraying layer and the unprotected slope surface shall be sealed

(10) the radial concrete shall be suitable for the thickness specified in the drawing, and expansion joints and drainage holes shall be set according to the drawing or at the instigation of the supervising engineer

(11) the rebound of radioactive concrete cannot be collected and put into the next batch to prevent affecting the quality of radioactive concrete

(12) radioactive construction should be suspended in the following environments

a. flush and refresh the cement on the spraying surface in rainy days to form concrete debris

b. the temperature is lower than +5 ℃

c. the archer stopped the task because of the big wind

3.4 anchor rod

(1) strictly follow the following sequence during construction: cleaning the slope, setting anchor rod holes, cleaning holes, grouting, placing anchor rods, installing end pads, and stopping other slope construction

(2) the hole forming and cleaning of anchor bolt holes should be selected according to the geological premise, and implemented after being approved by the supervising engineer

(3) the anchor rod body should be straight, derusted and degreased before use

(4) the common ratio of mortar for grouting: cement: sand should be 1:1 ~ 1:2, and the water cement ratio should be 0.38 ~ 0.45

(5) the mortar shall be mixed evenly. The mortar shall be divided into pressure shear and pull shear according to the test type. The mortar mixed at one time shall be used up before the initial setting, and stones and sundries shall be prevented from mixing

(6) when the grouting starts or stops halfway for more than 30min, use water or thin water slurry to smooth the grouting tank and its pipeline

(7) during grouting, the grouting pipe should be inserted to 50 ~ 100 mm from the hole bottom, and pulled out slowly and uniformly with the injection of mortar; After the rod is pulled out, if there is no mortar overflow at the orifice, it should be refilled in time

(8) the length of the rod body pulled out of the hole should not be less than 95% specified in the drawing. After the anchor bolt device, it is not allowed to knock casually, and no heavy objects should be hung within 3D

(9) each section of the project should replace the surface section to stop the pull-out test of the anchor rod. It is required that the pull-out force of the anchor rod should be greater than that specified in the drawing, and the construction parameters should be modified through the test to guide the large-scale construction

(10) the hanging shall be in accordance with the provisions of the drawings and approved by the supervising engineer. Reinforcement made of shallow galvanized iron wire with a diameter of 3 mm can be used

3.5 quality inspection

1 Basic requirements

the slope inspection items of anchor rod radioactive concrete and radioactive mortar slope should be appropriate table 3 Provisions of

inspection items of anchor rod radioactive concrete and radioactive mortar slope protection table 3

inspection item specified value or allowable error inspection style

1 concrete or mortar strength (MPA) within the qualified standard according to JTJ f80/Appendix D, e, f

2 anchor rod pull-out force (KN) pull-out force uniform value ≥ the drawing specified value, the minimum pull-out force is 0.9, the drawing specified value is 1% according to the number of anchor rods, and many of them do pull-out force experiments on 3

3 spray layer thickness (mm) uniform thickness ≥ the design thickness, 60% of the inspection point ≥ the design thickness, The minimum thickness is ≥ 0.5 design thickness, and ≥ 60. Check 1 section every 10m, check 1 point every 3M, drill holes or laser profiler to confirm the thickness

4 eye size (mm) 20 with a ruler, check 5 eyes every 10m

5 slope flatness (mm) 30 with a 2m ruler, check 3 places every 20m

note: the "every 10m or 20m" in Items 3, 4 and 5 refers to the length of the target along the line

2. Exterior identification

(1) it is roughly flat, and there is no exposed wire image of reinforcement and iron wire

(2) the length of the exposed rock surface of the bolt body should not be greater than the thickness of the radial concrete when using shotcrete bolt support

(3) the protection is generally smooth, dense and free of scattered scenes

(4) the expansion joint set is neat and vertical, and runs up and down

(5) the slope of the drain hole is outward, and there is no blockage

4, Enron, environmental protection, civilized construction

4.1 Enron production

(1) in line with the principle of "managing production must manage Enron" and "everyone is responsible for Enron production", resolutely implement the laws, regulations, goals and policies of the party and the state, safely establish the idea of "safety first, prevention first", and actively and seriously do the task of Enron production of the projects under its jurisdiction

(2) with a highly responsible attitude towards people and national wealth, the management staff included Enron production into the scope of the task, and understood Enron production system and Enron production goals

(3) seriously implement the laws, regulations, goals and policies of Enron production, strictly implement the rules, regulations and operating procedures of Enron production, and implement the "four all-round" static management of Enron production on the construction site as an enterprise imported from Jiangsu "vertically and horizontally to the edge", which is full staff, full process, all-round and all-weather

(4) for the style construction organization design, the design documents of each sub project must be checked in detail before the commencement of the project. According to the terrain, geology, hydrology, general scene and other data of the construction site, the appropriate Enron technical protection measures should be formulated during the style construction organization design. The Enron technical protection measures in this way should be reviewed by the supervision engineer and reported to the owner for implementation. It is strictly required to stop production safely according to the approved construction organization design

1) safety production rules and regulations must be formulated in the construction organization design

2) safe production technology methods must be formulated in the construction organization design

3) Enron production management organization must be implemented in the construction organization design

4) in the construction organization design, we must establish an Enron production guarantee system with Enron production system as the core

5) in the construction organization design, the production target of Enron must be divided and implemented to people

(5) for subdivisional works and temporary measures projects with high construction risks, high technical difficulties and frequent accidents, the contractor is required to submit the construction technical scheme of subdivisional works and the relevant mechanical calculation basis. The person in charge of technology strictly reviewed their Enron technical requirements and accident prevention methods, and insisted that the unfair plan did not pass, unqualified measures were not allowed to be used, unsafe actions were not allowed, and inaccurate calculations were not approved

(6) strengthen the education and training task of Enron production, improve the understanding and knowledge of Enron of all construction staff, and at the same time improve their own Enron essence and property level

(7) stop self inspection on the implementation environment of Enron production management institutions, systems and measures on schedule; Whether the number, nature and layout of full-time Enron personnel are reasonable; Whether the implementation of the Enron management system is implemented; Whether Enron warning signs and Enron advocacy are complete; Whether Enron's "three treasures" and other Enron supplies are sufficient

(8) hold a technical disclosure meeting on schedule, requiring that the safety disclosure must be stopped at the same time

1) technical disclosure, including Enron disclosure, must have written technical disclosure documents

2) technical disclosure, including Enron disclosure, must be targeted, comprehensive and operable

3) technical disclosure, including Enron disclosure, must be signed by all participants

(9) organize, implement and seriously implement the safe inspection system on the construction site. The inspection situation can be divided into comprehensive inspection and special inspection, regular inspection and irregular inspection, combined inspection and full-time staff inspection; The inspection cycle can be once a month, once a ten day or once a week according to the production environment of the site and the situation of Enron; The inspection contents shall be carried out in accordance with the provisions of JGJ "construction safety inspection standard", mainly including the implementation environment of the safety measures, the correction environment of the back chapter homework, and the perfect environment of the safety production measures of the key processes; All inspection results shall be submitted to the owner on schedule

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