Foundation and strengthening of the existing foundations, part 1

Foundation and strengthening of existing foundations

Foundation substructure is mainly used in these cases, when adjacent to an existing building (buildings) a new building is under construction, the foundations of which are located below the foundations of the existing building. On the other hand, the strengthening of the foundations is done by:

a) superstructure of one or two storeys,
b) additions to the existing building,
c) changes to the structural layout of the building,
d) partial damage to foundations by corrosion or other factors.

Before starting work related to both the foundation, as well as strengthening the foundations, the building structure should be protected against damage or destruction by the use of appropriate stamping and braces supporting the ceilings and walls. The punches and struts also absorb part of the loads acting on the structure.

tmp6f53-1tmp9301-1The order of tamping the foundations and the method of securing the excavations: a) the sequence of making excavations and tamping the foundation, b) detail of securing the excavation, c) the method of securing the building and excavation during the performance of works, d) horizontal projections of the shaft and bolts.

When erecting existing foundations, it is required, so as not to disturb the natural structure of the soil under the foundations anywhere. When the foundation is, for example, concrete, the foundation is made in lengths 1,0 – 1,5 m. After the foundation length has been divided into lengths 1 – 1,5 m, proceeds to select the soil in what 4 the field according to the markings given in the drawing.

Corners are built last. It is advisable to reduce the length of the sections for this reason, that the undermined corner works as a support.

After the excavations have been made and lined, the walls are supported with braces and the soil is well compacted, a brick wall is made on cement mortar., using as thin horizontal joints as possible. After the last layer of bricks has been laid, hardwood wedges are hammered between the old and new masonry in each row and the gap is filled with concrete., thickening it properly. Bricklaying of each section should be performed without working breaks, if necessary on 2 or 3 changes. In justified cases, the foundation may be made of concrete.

The requirements for the performance of works related to the foundation of the foundation are as follows:
a) making the foundation with short sections,
b) the shortest distance between sections, in which works are carried out simultaneously, should be 3 m,
c) execution of safeguards preventing any sliding or even loosening of the ground under the foundation.