it indicates a disorderly random path for moving water particles with lines of movement crossing and frequently moving at an angle or contrary to the general direction of flow.

two aquifiers under turbulent flow

read the effects of soil type: page 24

the action or method of removing subsurface water by means of channels, pipes or geosynthetics to render the area or structure useful.

read the purposes and benefits of drainage

it is understood that excavations extend below water table thus dewatering procedures will be required to keep the work area dry.

it is the procedure used to remove water from construction area, such as pumping from an excavation or location where water covers the planned working surface.

the type of soil in this excavation is coarse and the method is “open drainage or interceptor ditches”

the lowering of the level of the groundwater table that occurs in the vicinity of a water well (on dewatering equipment) when it is pumped.

small excavation or pit provided in the floor of the structure, or in the earth, to serve as a collection basin for the surface water and near-surface underground water.

Type of soil: coarse grained to silty Depth: more than 1 meter or a few feet below groundwater level

3 methods employed under dewatering intermediate depths

are a pictorial method of studying the path that moving water flows. are composed of flow lines and equipotential lines drawn together that form mesh strands

lines representing the path the water flows.

lines connecting points in the flow lines that are of equal total energy head.

is necessary due to limited height of lift for deeper excavation.

the perforated end section of a well pipe that permits the groundwater to be drawn into the pipe for pumping.

the application of vacuum to the piping system to satisfactorily dewater silty soils because capillary forces tend to hold the pore water.

A well or well point is made the cathode, pore water will then migrate toward the negative electrode (cathode).

are conditions where excavations extend deep below groundwater table or penetrate through a deep permeable stratum.

a subsurface drainage of fine-grained soils achieved by imposing a surface load onto an area resulting to decrease in water content followed by increase in shear strength.

Three conditions that take place simultaneously in consolidation drainage:

2 methods to accelerate consolidation

It is conventionally placed around the building exterior at footing level and adjacent to the footing.

a blanket or layer of filter material placed beneath the floor slab to provide a highly permeable drainage path for removal of groundwater.

are interceptor trench drains located parallel to the shoulder of paved highways and airfield runway.

localized underground flow that occurs through seams or a stratum of pervious soil presents a potential seepage problem for the structure.

localized underground flow that occurs through seams or a stratum of pervious soil presents a potential seepage problem for the structure.