Soil nailing

The soil nailing serves to ensure that excavations and steep slopes, especially in irregular slope profile without shoring. The pit is dug in sections, as far as the surrounding soil is momentarily stable. Subsequently, the bank is secured with reinforced shotcrete and soil nails, with a frictional connection is established between the nail head and shotcrete skin. The resulting composite in situ soil, then comprises the structural behavior of a gravity wall.

The soil nailing can be used both as temporary and a permanent measure.

Definition and standardization

It is in the DIN EN 1537 ( replaces DIN 4125 ) distinguished between anchors and nails. Nails are completely non-positively pressed onto the ground and are not biased. Anchor, however, have a defined Verpresslänge and a free, non-compressed region ( " free anchor length" ). Anchors are biased. Each anchor must be tested ( acceptance test ), with nails pull-out tests are performed only on a fixed number per site.

Production

For the preparation of a soil nail or Erdnagels a bore in the intended depth ( approximately 3 to 6 m) and in the secured inclination drilled wall. When drill rigs are used anchor drilling or drilling rigs. The bore is cased depending on the applied soil, prepared with worm hole or some other suitable method for the floor. The drill diameter usually depends on the incorporated Tagglied.

As a supporting member THREAD rods are often used. The hole is completely filled with cement mortar and optionally nachverpresst. The bond to the shotcrete lining is made with a nail plate and a mother. These are placed according to the preparation of the shell.

Construction Methods
Geotechnical Engineering

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