What is the development of the excavation?
The beginning of construction is necessarily based oncarrying out excavation works, so the technological map for the development of the foundation pit is created at the design stage of the facility. It finds a description of all the necessary activities. Therefore, the design of the pit should contain the entire sequence of actions - from site preparation, cleaning it from plants and old buildings, removing the fertile layer, taking out the prescribed volume of soil to producing holes, digging trenches, leveling slopes and grounds, allocating space for storing land before it is exported from the territory, etc.
Classification of excavations by designation
Technologies for developmentThe pit is divided according to two directions. One focuses on preparing the land for the construction of depressions and permanent channels. Their class includes objects of water reclamation, park and city fountains, ponds, artificial ponds, paths and embankments.
Temporary development of the excavation is necessary forconstruction of buildings and foundations for them. Classification of them by designation is intended for differentiation of types of work, under which it is necessary to use various mechanisms and special equipment. This takes into account the costs of manual labor. The greatest volume of non-mechanized work falls on the zones of location of underground engineering highways. They do not use excavators and graders. Any technical means can damage the padded cable or pipeline.
Also based on the classification of excavationsselect a set of activities to ensure safety in the areas where the excavation is being developed. They can consist in the installation of fences, identification and warning signs or the organization of the protection of the object.
Main types of work and their share in the total cost of the project
In terms of time, the development of a pit may take5 to 15% of the total time required for the construction of the facility. At cost, this is also not cheap. In the estimate documentation, usually excavation costs include a cost of up to one fifth of the total project budget. This is taking into account all measures for the vertical layout of the construction site, for the protection of the excavation from flooding by subsoil or sedimentary waters, for its waterproofing.
These include:
- Geodetic research.
- Stripping the site.
- Plot the site and mark the boundaries of the object.
- Excavation, digging trenches.
- Work to strengthen the slopes.
- Transportation, laying for temporary storage and disposal of excavated soil.
- The device of engineering communications.
- Filling and tamping the bevels at the outer edge of the foundation.
- Activities that divert groundwater from the site.
Importance of hydraulic engineering
Groundwater and rainwater can causehuge damage to construction. Therefore, the development of a foundation pit can not be done without taking into account the principles of hydraulic engineering. One of the first tasks of the engineer is to provide the site with protection measures. For this, canals that divert water are built, pits for water drainage are arranged, other types of receivers for liquids are used, from which they can be pumped out by drainage pumps.
