Re: Pile Socket

[ooox]

Hi all,

I have a few simple questions on piles sockets, have searched the internet but nothing seems to answer my question.

1.What is the purpose of socketing a pile into rock/clay/sand?
2.What dicates the length of socket?

Thanks all.

 

[bridgebuster]

A rock socket provides resistance to uplift or lateral capacity.

Uplift capacity in rock is based on friction between the vertical surface of the pile and the rock.

The lateral resistance of the socket is based on passive pressure, same as for soil but the friction angle is higher.

 

[Qshake]

Agree with bridgebuster. Would like to add that some codes, AASHTO for one, notes that pile expected to be driven less than 10' shall be socketed no less than 10'. Also in some cases, geotechs will recommend grouting the pile in rather than sand backfill.



Regards,
Qshake

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[hokie66]

999,
You asked about socketing into rock/clay/sand. The term socket is usually reserved for rock sockets, and refers only to the bottom length which penetrates rock rather than other soil. The length of the socket can be used to resist both gravity and uplift loads by skin friction.

 

[HSNIC]

I know rock sockets from drilled pier construction. Usually, you get the depth to competent rock and the structural engineer tells you the load to counter with.

Knowing the compressive strength of the rock and concrete-bedrock bond stress, a socket depth is dictated for skin friction and end bearing.

I was involved in the field inspection for rock sockets. The socket inspection was done via camera. Pretty cool stuff!