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Earthworks

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Excavation work Coursework

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icon proizvodstvo_zemlyanyh_rabot.rar
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Additional information

Contents

INTRODUCTION

1 DETERMINATION OF EARTHWORKS

1.1 DETERMINATION OF EARTHWORKS DURING SITE PLANNING

1.1.1 Definition of Black Elevations

1.1.2 Determination of red marks

1.1.3 Determination of operating elevations and establishment of mass haul contour

1.1.4 Determination of number of leading earthworks for site planning

1.2 DETERMINATION OF EXCAVATION VOLUMES IN CASE OF EXCAVATION OF PITS AND TRENCHES FOR COMMUNICATIONS

1.3 BALANCE OF EARTH MASSES AND CARTOGRAM OF EXCAVATION VOLUMES

1.4 DISTRIBUTION OF EARTHEN MASSES

1.4.1 Construction of the initial matrix

1.4.2 Develop an optimal mass haul distribution plan using linear programming methods

2 SITE PLANNING EARTHWORKS TECHNOLOGY

2.1 DETERMINATION OF WEIGHTED AVERAGE RANGE OF BALANCED SOIL AT SITE

2.2 SELECTION OF EARTHWORKS

2.3 DETERMINATION OF DESIGN TRAJECTORY OF EARTH-MOVING VEHICLES MOVEMENT ERROR! BOOKMARK NOT DEFINED

2.4 DETERMINATION OF NUMBER OF LEADING EARTHWORKS FOR SITE PLANNING

2.5 DETERMINATION OF NUMBER OF AUXILIARY MACHINES AND COMPOSITION OF TEAMS FOR EARTHWORKS ON SITE PLANNING ERROR! BOOKMARK NOT DEFINED

2.6 DESIGN OF PREPARATION WORKS ERROR! BOOKMARK NOT DEFINED

3 TECHNOLOGY OF EARTHWORKS DURING DEVELOPMENT OF PITS AND TRENCHES

3.1 SELECTION OF EXCAVATOR FOR EARTHWORKS

3.1.1 Development of pits

3.1.2 Trench Development

3.2 SELECTION OF TYPE OF PENETRATIONS AND DESIGN OF EXCAVATOR FACE

3.3 PREPARATION OF OPERATIONAL JOB INSTRUCTION DURING SITE PLANNING

3.4 EXCAVATION IN WINTER CONDITIONS. INSULATION METHOD

3.5 GROUND SAFETY GUIDELINES

3.6 EXCAVATION TECHNOLOGY FOR PIT AND TRENCH DEVELOPMENT

CONCLUSION

LIST OF SOURCES USED

Introduction

During the construction of any building or structure, as well as the planning and improvement of territories, soil processing is carried out. Processing includes the following main processes: soil development, its movement, laying and compaction.

This process is in some cases preceded or accompanied by preparatory and supporting processes. Preparatory processes are carried out before the beginning of soil development (cleaning of the territory from plantations), and auxiliary processes - before or during the construction of structures.

Earthworks are expensive and particularly labour intensive. So, for example, in industrial construction, they amount to about 15% cost and 18... 20% labor intensity of the total volume of work. About 10% of the total number of construction workers are employed in earthworks.

In course work, it is necessary to plan the construction site, calculate the volumes of earthworks during the extraction of pits and trenches, select the necessary excavation machines, calculate the technical and economic indicators of the work.

Source Data

Coordinates of corners of the platform: A5,Zh5,A12,Zh11;

The size of the sides of the squares is 50 m;

Horizontal drop - 0.92 m;

Soil - fine sand;

Layout plane position - with zero balance;

Slope of the layout plane - to the minimum of earthworks;

Version of the construction under construction - 1;

Type of communication - water supply;

Pipeline diameter - 0.8 m;

Outside air temperature - 20;

Ground freezing depth - 1.4 m;

The method of development of frozen soil is loosening.

Determination of excavation quantities

1.1 Determination of excavation scope during site planning

1.1.1 Definition of Black Elevations

According to the assignment of the course work, we select a construction site with a certain terrain, sign contours with a given drop - 0.82 m. The size of the side of the grid cell in accordance with the assignment is 50 m.

You define black elevations in the grid nodes by interpolating the shortest distance between adjacent contours and applying it in the drawing to the accuracy of 0.01 m to the right, at the bottom of the node in black.

1.4 Mass Haul Distribution

The task of mass haul distribution is to establish the optimal amount of soil sent from the i-th elementary section to the j-th elementary section of the embankment.

You can find the optimal solution to this problem using linear programming methods, in particular, methods for solving the transport problem.

Design of preparatory works

Preparatory work during site planning includes: clearing the construction site from forest, stumps, shrubs, rolling trees for forest removal, cutting shrubs and small forests, breaking stumps, stones and roots and their harvesting, clearing from boulders, removing the plant layer and loosening the soil.

The line forest is sawed with motopils followed by stumps. Trees that are not used as business wood are felled together with the roots, while the energy cost will be much less than when felling with subsequent stumps.

For felling trees with roots and rooting individual stumps, roosters-gatherers or bulldozers mounted on tractors are used. The thickness of the trees to be piled depends on the power of the tractor, the density of the soil and the location of the roots in the ground. When rolling trees with a root system lying parallel to the surface of the earth (spruce, etc.), 2025% less energy is required compared to trees of the same thickness with vertical roots (pine, oak ).

Roosters can also clear stones and boulders.

After selecting the machines to clear the site, the scope of work is set.

Technology of earthworks during development of pits and trenches

3.1 Selection of excavator for earthworks

3.1.1 Development of pits

It is required to select an excavator for the development of a pit in the soils of the first group with a volume of 1300 m3 and a depth of 1 m. The groundwater level lies below the bottom of the pit. The capacity of the excavator bucket is taken to be 0.4 m3, respectively, the excavator EO302B is selected. The maximum digging depth of the reverse shovel at q = 0.4 m3 in the pit is 2.6. Therefore, at a depth of 1 m, the development of the pit by the excavator EO302B can be carried out with reverse shovel equipment.

3.1.2 Trench Development

It is required to select an excavator for the development of a trench for heating in the soils of the first group. The depth of the trench is constant throughout the length of the trench and is 1.4 m, the width along the bottom is 0.7 m. The groundwater level lies below the bottom of the trench. It is economically advantageous to choose the same excavator with the same equipment as for digging a pit. Therefore, we choose the excavator EO302B with reverse shovel equipment .

3.2 Selection of type of penetrations and design of excavator face

The excavator, regardless of the type of working equipment, develops pits or trenches with continuous movement along their longitudinal axis. Depending on the working conditions of the excavator, frontal (end) and transverse-frontal (end) faces are used.

Depending on the type of face, the penetration is frontal, end, side, etc. The type of penetration depends on the direction of soil unloading by the excavator, the size of the excavation and the parameters of the working equipment of the excavator.

The correct choice of the type of penetration allows you to rationally organize the work of the excavator and vehicles.

After selecting the type of penetration, the design of the face is started, which consists in determining the most optimal dimensions of the face, the mutual position of the excavator and vehicles.

3.4 Excavation in winter conditions. Loosening method

Soil loosening can be carried out by explosive or mechanical method

Mechanical loosening is divided into three types: static, dynamic and cutting frozen soils.

Mechanical loosening is used in the passage of small-volume pits and trenches. In these cases, frozen soil to a depth of 0.5... 0, 7 m is loosened with a wedge hammer suspended from the boom of the excavator - the so-called loosening by splitting. When operating with such a hammer, the boom is installed at an angle of at least 60 °, which provides a sufficient hammer drop height. When using free fall hammers, due to dynamic overload, the steel rope, trolley and individual machine units quickly wear out; in addition, from impact on the ground, its vibrations can adversely affect nearby structures.

The soil is loosened with mechanical rippers at freezing depth more than 0.4m. In this case, soils are loosened by chipping or cutting blocks. The number of impacts on one trace depends on the freezing depth, group of soil, mass and height of the hammer.

Impact freezers work well at low ground temperatures, when it is characterized not by ductility, but by brittle deformations that contribute to its splitting under the influence of impact.

Soil loosening by tractor looseners. This group includes equipment in which the continuous cutting force of the knife is created due to the traction force of the tractor driver. Cars of this type layer by layer pass frozen soil, providing for each penetration the depth of loosening 0.3... 0, 4 m. static rippers can be trailed and mounted. Very often they are used together with a bulldozer, which in this case can alternately loosen and develop soil. Soil is loosened by parallel penetrations with subsequent penetrations at an angle of 60... 90 ° to the previous ones .

Explosive method

Explosive method of soil mining is used for loosening of rock and frozen soils, as well as for arrangement of excavations for artificial reservoirs and canals, dams, selecroofing structures. Ammonite, tol, TNT are most often used as an explosive. The necessary explosion energy is obtained by selecting the type of BB. its location in the ground and the charge blasting sequences. This makes it possible to carry out a directed release of soil, ensuring its movement in the desired direction and laying.

The placement of charges in the ground can be overhead and internal. At overlay method charges are placed on surface of medium, at internal - in pre-prepared holes, wells, chambers or slots.

Spur Charge Method

They are used in open and underground developments with small volumes of simultaneously exploded soil. Holes are arranged with a diameter of 25... 75 mm, and they are placed in one or more rows along the face. Explosive is filled with not more than 2/3 of the hole height (length), and its upper part is clogged with sand or drilling fines

Downhole charge method

Used when loosening a large mass of soil or for dumping rock. Its difference from the method of bore charges is that wells with a diameter of 200 mm or more are arranged to accommodate explosive. The upper part of the well is also clogged with drilling fines or sand.

Chamber charge method

It is used in the development of pits and channels of significant sizes and for the production of directed soil discharge. The method consists in the fact that in the area of the developed soil vertical wells (pits) or horizontal galleries (galleries) are arranged, from which chambers are opened in lateral directions to accommodate large concentrated charges. Wells and adits after placing charges in them are clogged with soil. Directional ejection is provided by arrangement of charges in two rows along future recess with increase of explosive mass in one of rows and their delayed explosion.

Slit Charge Method

Used when loosening frozen soils. To do this, using a discofree or bar machine at a distance of 0.5... 2.5 m from each other, paired slots are cut to the depth of ground freezing. Explosive charge is laid in one of the slots, the other is left empty as compensating. From the explosion, the soil located between the charging and compensating slots is crushed and simultaneously shifted towards the compensating slot. Several slots are cut on large areas, and charges are laid through one slot. Explosive work, and especially mass explosions, is carried out according to special projects that determine the methods of explosion, the placement of charges, the order of laying explosive chambers or wells and the sequence of explosions.

3.5 Ground Safety Guidelines

In the course design, measures should be provided to ensure the stability of slopes of the developed pits and trenches.

Earthworks shall only be performed according to the approved work design. In the presence of underground communications in the excavation area, any excavation can be carried out only in the presence of a representative of the organization operating these lines. Excavations shall be designed with slopes provided by SNiP. The recesses shall be free of static and dynamic loading. During the development of excavations with vertical walls, the fasteners should be installed immediately after the permissible depth of penetration with vertical loose walls is reached for this type of soil. When filling such recesses, remove the attachments from the bottom up. Soil visors formed during the pit development should be collapsed, while taking all precautions and removing preliminary workers from the face.

Vehicles and earth-moving vehicles moving along the filled embankment should not approach the edge closer than 0.5 m. When working at night, workplaces should be illuminated, and earth-moving, transport and earth-moving vehicles should have individual lighting.

When excavating soil with excavators, workers are forbidden to be under the bucket or boom and work from the side of the face. Unauthorized persons may be located at a distance of at least 5 m from the range of the excavator. The excavator can move only along an even surface, and in case of weak soils - along the flooring from sleepers or shields. When preparing the track for moving the excavator, the ladle must be taken aside and lowered to the ground. When transferring the excavator through the railway track, the latter must be paved with sleepers or logs. The marginal slopes during the operation of the scrapers are as follows: longitudinal 10 °, transverse 18 °.

During bulldozer operation it is prohibited to turn it with dump loaded or buried in the ground to avoid breakage or overturning. Do not move the ground by bulldozer to rise more than 10 ° and at a slope of more than 30 °, as well as extend the dump beyond the edge of the excavation slope (when the soil collides under the slope). On rough terrain and along a bad road, the bulldozer should only move with low engine gears.

During hydromechanical soil development the territory shall be protected and warning inscriptions shall be installed. The bottomhole shall have telephone communication and alarm means for communication with the pump station, control room and the washing area. Before the works start, there should be no workers in the area of the jet action and at the top of the face (possible prism of collapse).

Telephone communication and alarm are necessary when moving soil by belt conveyors.

When tillage of soils by the impact method, it is necessary to determine the dimensions of the hazardous zone by the spread of pieces of soil, remove people from this zone and install protective devices on the crushing machine. When the frozen soil is heated with electrodes, it is necessary to shield the area under voltage. Any work in this area is allowed only after the current is cut off.

3.6 Environmental measures

Construction of the facility is preceded by site engineering preparation. In this case, the composition of the processes can be different and depends on the local conditions of the construction site and its position. In general, these processes include clearing the site area, removing surface and ground water, and creating a geodetic breakdown base.

When clearing the territory, we transplant green spaces, if we use them in the future, protect them from damage, feed stumps, clean the site from shrubs, demolish or disassemble unnecessary structures, remove a fertile layer of soil.

Green spaces that are not subject to cutting or transplantation are covered with a common fence. The trunks of separate trees falling into the work area are protected from damage, covering them with lumber waste. Separate bushes transplant. Trees and shrubs suitable for landscaping are dug or transplanted into a specially designated protection area.

We clear the territory from the shrub with bushes. For the same operation, bulldozers with tooth growers on the dump, roosters-gatherers are used. Cushions are replaceable equipment for a caterpillar tractor.

Immediately after cleaning the territory from stumps and tree trunks, we choose fragments of roots from the vegetable layer with parallel transitions of rootstocks with widened dumps. Removed roots and remains from the cutting of trees are removed from the cleared area to specially designated places for subsequent export or incineration.

The fertile soil layer to be removed from the site is cut off and moved to specially designated places where it is stored for subsequent use. Sometimes it is taken to other landscaping sites. When working with a fertile layer, it should be protected from mixing with the underlying layer, from contamination, erosion and weathering.

Building sites are enclosed or marked with appropriate signs and inscriptions.

Conclusion

During the course work, volumes were calculated during site planning and separation of pits and trenches. The volume of excavation during site planning was 25,724 m3, excluding the unbalanced embankment equal to 5323 m3, during the development of pits and trenches - 3777 m3. When planning the site, a scraper and a bulldozer are involved. The bulldozer performs work in the field of zero lines, and the stapler develops the rest of the site. Optimal trajectories of earth-moving machines were also selected, the main parameters of the machines were calculated. Measures are provided to protect the soil from freezing, in our case, the soil insulation method with straw and snow is used. An excavation schedule was drawn up at the construction site. As a result, earthworks must be carried out in 15 days.

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