Construction production technology

Contents

1. Introduction

2. Characteristics of the structure, its design features

3. Composition and scope of construction and installation works

4. Preparatory and ancillary work

5. Breakdown of structures, pits and trenches on the ground

6. Determination of dimensions and volumes of excavation works for pit arrangement

7. Definition of concrete and erection types of works

8. Concrete works

9. Installation of valves

10. Formwork

11. Selection of equipment and methods for earthworks

12. Selection of equipment and methods for earthworks

13. Organization of drainage, drainage and artificial

lowering of groundwater level

14. List of used literature

1. Introduction

Construction production combines two subsystems: technology and organization of construction production, each of which has its own essence and scientific foundations.

Design and survey work is one of the important links of capital construction. Designers stand at the origins of construction projects, lay the economic and qualitative foundation for the created objects. The efficiency of capital investments, the increase in technical level, productivity and working conditions - all this largely depends on what technical and technological solutions, construction structures, equipment and materials are laid down in the project.

2. Characteristics of the structure, its structural features

Radial settling tanks are round in plan tanks in which waste water is supplied to the center of the settling tank and moves radially from the center to the periphery. The speed of the clarified water varies from the maximum values in the center to the minimum at the periphery of the radial sump.

The circular shape of the radial sumps allows to reduce the required thickness of the wall panels due to the use of high-strength prestressed reinforcement, which reduces their specific material intensity.

The relative simplicity of settling facilities makes them widely used in various stages of treatment of waste water and treatment of formed sediments.

4. Preparatory and ancillary work

Before the start of the main works during the installation of earth structures perform preparatory works: off-site and on-site. Off-site preparatory works include: construction of access roads, communication and power transmission lines, performance of overburden work in areas reserved for quarries and reserves, to on-site works - restoration and fixation of the geodetic breakdown base; clearing of the construction site area; engineering preparation of the site with execution of works on planning, drainage and provision of rainwater runoff, arrangement of temporary (or permanent) roads and communication networks; installation of temporary inventory rooms for heating workers, eating, drying and storage of working clothes, bathrooms, etc.

Preparatory works are preceded by organizational measures to receive permits from the customer-developer for the removal of land plots; construction works; use of existing transport and utilities; cutting down trees, etc.

Geodetic works shall include: creation of a breakdown structure and performance of the breakdown works during construction performed by the construction organization.

Clearing the territory of the construction site includes work on cleaning trees, shrubs and boulders, freeing the territory from buildings to be demolished, transferring existing communications, etc.

For the convenience of tree rolling and work safety, the territory is previously cleared from shrubs and shallows, which are uprooted with the help of bushes, bulldozers, crust tractors and removed to specially designated places.

Excavations of all types prior to the start of the main excavation works shall be protected from the surface water riser by means of permanent or temporary devices. Drainage devices shall ensure the interception of upland waters along the boundary of the construction site or trench and accelerate the flow of water from the site. For drainage, to arrange cavaliers and dumps, as well as special fencing, drainage drainage ditches, to plan the territory with a slope. Cross-sections and slopes of all drainage devices shall be designed for the passage of stormwater and water generated by snow melting.

The brow of the drainage channels should be higher than the design water level by 1020 cm, their depth - 0.6 m, width along the bottom - 0.60.8 m.

Prior to the start of excavation work on vertical layout, cut of excavations, installation of embankments within the construction site, the vegetation layer of soil must be removed and laid in dumps for further use.

Perform auxiliary works during installation of earth structures. They include temporary anchorages of walls and trenches and pits, open drainage and soil waterfall, artificial behind-fixation of soils.

5. Breakdown of structures, pits and trenches on the ground

The main layout axes of the structures with construction duration up to 5 months and on-site utility networks shall be fixed with geodetic signs in the form of a metal rod 57 cm long, clogged into the ground by 50 cm.

Before starting, check the correctness of the breakdown of the structures in kind and draw up the corresponding certificate, with the appendix of the breakdown diagrams to it.

The excavation of the pit on the terrain should be started with fixation of con-tours of its edge and bottom by rings, using, for this purpose, mutually perpendicular extreme or central main axes of the structure according to the survey geodetic scheme and geometric dimensions of the excavation. After that, around the future pit at a distance of 2... H m from the brow, install a cover consisting of metal or wooden posts dug into the ground and at-fastened to them strictly by one level of rack boards. On the upper edge of the boards, remove the axle slats and attach them with nails or hairlines. Periodically tighten axial wires along the cover, using plumbs to monitor the accuracy of the pit passage, in the future use axial wires for the structure base device. The horizontal plane of the top of the racks allows (did not resort to leveling) to check the digging mark in any part of the pit.

Piping trenches shall be split based on geodetic layout, longitudinal and transverse profiles. Fix the axis of the route on the ground with milestones (for 2... 2.5 m), driven into the ground after 10 m on straight and 5 m on curved sections, as well as at the angles of rotation of the route and the locations of wells. Install rails on lugs along the leveling parallel to the trench slope line. On the rack, mark the width of the trench above and below. During the passage, check the level of the trench bottom between adjacent lugs using the running sighting.

8. Works on construction of bases and foundations

Bases mean the strata of soils that perceive the load from a building or structure. There are natural bases, composed of natural soils, and artificial. The purpose of sub-preparation of the base is to create a reliable contact of the foundation with the base.

The strength and stability of the constructed buildings and structures largely depends on the quality of the base preparation. At the same time, it is very important to compress the bases, carried out in order to increase their strength and reduce the precipitate of buildings and structures.

Surface compaction shall be performed by layer-by-layer compaction of soil by means of mechanized ramming.

9. Concrete works

For the construction of water supply and drainage systems, use hydraulic concrete, characterized by increased strength, waterproofness, water and frost resistance.

The process of preparing the concrete mixture should include the steps of receiving and storing the constituent materials, dosing and mixing with water, as well as issuing the finished concrete mixture to vehicles.

Concrete mixture manufactured in centralized concrete plants shall be brought to the construction site according to the work schedule.

Transportation of the concrete mixture includes delivery of it from the place of preparation to the construction object, supply of the mixture directly to the place of laying and distribution to the place of concreting. During transportation, the mixture is protected from atmospheric precipitation, freezing, drying, as well as the flow of cement milk.

To transport the mixture to the facility, road transport should be used - general-purpose dump trucks, concrete trucks, and concrete mixers .

Rotary trays with a capacity of 0.50.8 m3 are loaded directly from dump trucks or concrete locomotives.

The mixture should be laid in horizontal layers with thickness of 3050 cm over the entire area of the concreted part of the structure. At the same time, all layers are laid in one direction, of the same thickness, continuously over the entire height and carefully compacted. Compaction of the concrete mixture is necessary to improve the quality and strength of concrete structures, carried out by vibration or vacuuming. Use surface vibrators installed on the laid concrete mixture, transmit oscillations to it through the working site. Concreting of the bottom is performed in the form of seven grips, first pour 1, 3, 5, 7, give concrete time to acquire the necessary strength (70%), then pour 2, 4, 6, 8 grips. Perform the works according to the work schedule.

10. Installation of valves

Install reinforcement frames to self-propelled cranes MKT16 using special crossbeams. The frames of foundations and sub-columns of high mass at a height of more than 2 meters should be installed by crane using self-balancing slings. Mount flat grids and wireframes. Individual rods shall be installed during reinforcement in the structure formwork.

Use arc welding to connect rebars, grids, and frames.

Install the panels in the bottom slot from the parking of crane No. 1, install the panels from the first to 37, then install the panels from 37 to 43 from the parking .

11. Formwork

The formwork is designed to give the structures to be erected a design shape, given dimensions and position in space. Put the concrete mixture in the formwork and hold it in it until it achieves the fracturing strength. According to the materials of the forming surface, take a wooden formwork. Formwork shall be arranged according to the work schedule.

14. Organization of drainage, drainage and artificial lowering of groundwater level

Drainage is necessary to protect pits and trenches from flooding with stormwater and meltwater. For drainage, reserves, cavaliers, as well as specially installed fencing, drainage ditches, trays and drainage systems are usually used on the upland side. Ditches or trays are arranged with a pro-longitudinal slope of 0.002-0.003, and their sizes and types of fasteners are taken depending on the consumption of storm or meltwater and limit values ​ ​ of non-washing speeds of their flow. Divert water from all drainage devices, as well as from reserves and cavaliers to reduced places remote from erected and existing structures.

Drainage. Preliminary drainage is often carried out during the construction of pits and trenches, since most structures and networks of water supply and drainage are erected either in the immediate vicinity of reservoirs, or in conditions of watered and unstable soils. Excavations (pits and trenches) with a small influx of groundwater are developed using open drainage, and if the current is significant and the thickness of the water-saturated layer to be developed is large, then before the start of work, the groundwater level (UHF) is artificially lowered using various methods of closed, i.e., groundwater, drainage, still called construction waterfall.

The initial drainage of the pits is required after guarding them with bridges. Type and number of pump units are selected by value of volume of initial water drain. Divided into: open drainage and artificial lowering of groundwater levels.

Use open drainage.

The open drain provides for pumping of inflow water directly from the pit or trench. In case of open drainage, groundwater, leaking through slopes and bottom of the pit, enters catchment ditches and through them into sumps (sumps), from where it is pumped out by pumps. The system of pumping units pumps water into the catchment number-lecturer and discharges it through it outside the pit. Open drainage is a rather efficient and easy way to drain the pit and trench.

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