## Water Flow through a Vertical Column

## Water Flow through a Vertical Column

(OP)

I am trying to find the total head for different locations along this vertical column with soil for work. It has been a long time since I have done it, so I want to make sure that my method is correct. My water level is 30 meters from the bottom and my soil surface is 20 meters from the bottom. It is my understanding that the total will not change along the column (constant). Is this correct?

## RE: Water Flow through a Vertical Column

f-d

¡papá gordo ain’t no madre flaca!

## RE: Water Flow through a Vertical Column

## RE: Water Flow through a Vertical Column

## RE: Water Flow through a Vertical Column

## RE: Water Flow through a Vertical Column

Fundamentally, this all relates to Darcy's law; v=ki or q=kia

You are ultmately striving to determine the "i" term, or gradient, which is related to the length of flow and the head conditions at the upstream and downstream observation points. You have some sense of "q" (i.e., 40cc/sec). So, now we can't help you with either "i" or "a." You got the "q" though. . .

f-d

¡papá gordo ain’t no madre flaca!

## RE: Water Flow through a Vertical Column

## RE: Water Flow through a Vertical Column

f-d

¡papá gordo ain’t no madre flaca!

## RE: Water Flow through a Vertical Column

## RE: Water Flow through a Vertical Column

I recommend checking out Lambe and Whitman's Soil Mechanics, page 252 for a refresher/further explanation.

## RE: Water Flow through a Vertical Column

Q=kia, where

Q=40 cc/sec

k=permeability (unknown)

i=hydraulic gradient, DeltaH/DeltaL

DeltaH is the head loss that occurs over the length of the sample

DeltaL is the length of the sample.

A=78.5cm2

Using a bit of algebra, I get k=3.4x10^-1cm/sec

f-d

¡papá gordo ain’t no madre flaca!

## RE: Water Flow through a Vertical Column

## RE: Water Flow through a Vertical Column

## RE: Water Flow through a Vertical Column

f-d

¡papá gordo ain’t no madre flaca!