Digital Seismometer Installation - Vault Construction

A hole was dug until we found bedrock at a suitable depth.

Professor Key measuring depth to bedrock.

Jeff Roth (right) leveling the 8" round concrete mould that will become the pillar for the instrument.

The concrete after it was poured and leveled. We used a fine-grained, non-shrinking, precision grout for the pillar. Don't forget to scribe a North reference!

The instrument will sit like this on the pillar.

It will then be covered with an insulative cap. We made this out of 2 styrofoam insulators that are used for shipping acid bottles (some had to be cut from the bottom of one and glued to the other to make it tall enough).

The vault wall is made of 12" diameter, thick-walled PVC.

We poured sand around the pillar to allow for drainage of any water that might leak in to the vault or condense inside.

We then seated the vault around the pillar.

A look inside the vault.

The vault was covered to keep out debris, and then the hole was carefully backfilled.

Conduit was laid from the vault to the building. There are 2 conduits - one for power, and one for data.

A GPS antenna is used for accurate timing and had to be installed on the roof.


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This page was last updated on Mon,28 March, 2005 16:39
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