culvert Archives - Civil Engineering Tips

Culvert location guide can be discussed as follows as it located in various geographical conditions and climate variation.

(a) In general, the flow line of a culvert should conform as nearly as practicable to the gradient and direction in the stream bed or channel.

(b) The stream should have a direst any an entrance and exit on the culvert. Abrupt adjustments to direct can cause turbulence and the probability of scouring in some aspects of the stream and silting in other.

The ideal grade line for a culvert is one that produces neither silting nor excessive velocities and sour. Normally the grade type of the culvert should coincide while using stream bed, however, in most circumstances it may be desirable to deviate from it e.g.:-

• Where sedimentation is anticipated that occurs the culvert invert may be set several inches higher compared to the stream bed, but on a single slope.

• Where headroom is limited, setting a culvert below stream bed grade is likely to result in sedimentation and reduced waterway area. This should be avoided either by using a low, wide culvert say for example a box culvert or a pipe arch, or by raising the street grade.

• In steeply slopping areas, as on hillsides, it’s not always necessary to put the culvert on the same steep grade. The culvert can be put on the ‘critical’ slope and then a spillway provided in the outlet in order to avoid scouring. This prevents the culvert shorter and under shallower cover.

• At times a shorter length of culvert can be used and/or a better foundation obtained by shifting the culvert to one side of the natural channel. When this is done, care should be arrive at construct the inlet and outlet channels to supply for a smooth flow from the water, particularly around the downstream side in order to minimize or prevent erosion.

Not only above, as culvert location guide but also varied conditions apply with different kind of project around the world.

Preliminary Planning of Culvert Construction

The preliminary planning of culvert construction would be to study the drainage plans and specifications, and inspect your website to determine the resources required and plan the works.

There are a variety of matters which must be considered inside preliminary planning with the work. These are generally:-

(1) The construction safety regulations that might connect with the task, e.g. requirements for shoring trenches, etc.

(2) Location of public utility services which may be affected by the work and the agreed procedure to be adopted for the notification of utility authority. The utility authority ought to be asked to find and mark in the grass the positioning with their facility which can be affected by construction. Too great a credence mustn’t be added to the records of the utility authority. These records in many cases are inaccurate or incomplete. In which a service requires re-adjustment, early advice ought to be fond of the service authority as this work often cannot be given priority on the authority’ normal work.

(3) Subsurface conditions. Where significant amounts of excavation are involved, the site (and site investigation reports where available), should be examined to gain a standard knowledge of the subsurface condition.

(4) provision for traffic side tracks, etc.

(5) Planning and scheduling in the works in terms of the earthworks operations. No less than a number of the drainage work will likely be around the “critical path” and unless it’s commenced and completed promptly, the entire project may be delayed.

(6) The need to determined the center line and invert levels of the pipe on the ground well ahead with the start at work. Normally this setting out is performed with the supervisor after which it checked with the supervising engineer as it is often the engineer’s responsibility to ensure culverts are correctly located knowing that invert levels are such that effective drainage is achieved. ( In most cases, large complicated drainage structures and critical skew angles has to be set out by the engineer.) Should the supervisor consider that the pipe location requires changing, he or she must refer his proposal for the engineer before any tasks are undertaken. In some cases such proposals may involve design changes requiring Divisional Office approval. In such instances it takes time to obtain the necessary approvals. And this highlights the need for all drainage sites being examined very early in the task to be sure that construction delays are avoided.

These steps are following as general guide lines to preliminary planning of culvert construction and it might be changed according special job site culvert construction.