Shoring

Shoring – Introduction

Shoring is designated to protect workers from cove-ins when excavating a trench for repairs or new construction, shoring supports walls of a trench through a wooden or metal framework.

Shoring framework typically consists of wooden or metal sheeting along the face of the trench wall supported by uprights, horizontal stringers placed along the uprights, and braced which attach to the stringers and span the excavation.

Shoring is the process of supporting a building vessel, structure or trench with shores (props) when in danger of collapse or during repairs or alterations. Shoring comes from shore a timber or metal prop. Shoring may be vertical, angled, or horizontal. Or they are temporary support given to a wall and floor during alteration work, demolition or underpinning and where structure becomes unsafe. With the primary aim of providing the necessary precaution or many form of collapse or damage to the structure, they render lateral support to walls under the following circumstances:

• Bulging out wall as a result of poor workmanship
• Cracking walls as a result of uneven settlement of subsoil (sub structure)
• Support during alteration.

Raking shores: this is the system of giving temporary support to an unsafe wall. The construction of raking shores also known as inclined shore, varies with the conditions of site in all cases wall-plate 23cm x 5cm to 23cm to 76cm. it size is fixed against the unsafe wall with hooks.

The wall plate is further secure to the wall by means of needles which are 10cm x 76cm in section penetrate inside the wall for a distance of about 10cm in turn. The needles are strengthened by providing wooden cleats. The top of the end of the included rakers rest against the needles.

At their base the rakers are supported by a sole piece bedded in an inclined position in the ground. The rakers are secured to the sole piece by cleats and dogs. In the soft ground the area of the sole piece in increase so as to distribute the pressure over large area.

In places where more rakers are provided, they are bound together by means of hoop. Iron or braces 25cm thick and 15cm wide. The inclination of the outer rakers to the ground should vary between 60⁰ to 75⁰. The sets of shores should be usually placed at 3 to 40m center to center along the wall length.

Function of Raking Shore

Raking shore is provided to support the wall from above the proposed opening to safe guard against shocks and vibrates during wall cutting.

2. Dead or vertical Shore: This system of shoring the vertical members known as dead shores are used to support temporarily the walls, roofs floors etc by providing horizontal member known as needle.

Functions

1. To rebuild the lower part of a detective load bearing wall.
2. To rebuild or replace or deepen the existing foundations which have either becomes unsafe or require strengthening for carrying heavier loads.
3. To provide large opening in the existing walls such as doors, windows, or garages at a lower level.

3. Flying or Horizontal Shores: These are types of Horizontal supports that are provided for supporting temporarily the parallel walls of the two adjacent buildings, which may tend to collapse or damage when one of the intermediate buildings has to be pulled down and rebuilt.

Functions

They are used to support the party walls of the houses adjoining the premises being rebuilt. These types of shores are only possible where sap between adjacent building.

These types of shores are only possible where the sap between the two buildings is quite small. They can be used as advantage of allowing passage under them.