Curb Inlets On-Grade. The design of on-grade curb opening inlets involves determination of length required for total flow interception, subjective decision about actual length to be provided, and determination of any resulting carryover rate.

An inlet on grade has a positive longitudinal gutter slope. Its interception capacity, Qi, is the flow intercepted by an inlet under a given set of conditions. The efficiency of an inlet, E, is the percent of total flow that the inlet will intercept for those conditions.

pavement drainage design on the performance of curb-opening inlets on grade. Curb-opening inlet capacity depends on the inlet dimensions, longitudinal slope, gutter and roadway cross slope, local depression, and approach flow characteristics. Curb-opening inlets are effective at capturing flow from the roadway in many situations

Curb opening inlets are useful in sag and on-grade situations because of their self-cleansing abilities and hydraulic efficiency. Additionally, they are often preferred over grate inlets because the inlet is placed outside the travel way and poses less of a risk to motorists and bicycle traffic.

The capacity of inlets on grade will depend on interception capacity and the amount of carry over that is allowed. If curb inlet extensions are used with the curb inlet, they shall be place on the up gradient end of the curb inlet.

On-Grade – Smaller throat can constrict flow, but excess diverted to next section – Similar results with high tailwater Research Recommendation - No change due to throat constriction for on-grade PCO inlet extensions

7.4.2 GRATE INLETS ON GRADE (UNDEPRESSED: TYPE B-2) Undepressed grate inlets on grade have a greater hydraulic capacity than curb inlets of the same length so long as they remain unclogged. Undepressed inlets on grade are inefficient in comparison to grate inlets in sumps.

This Technical Note (TechNote) addresses a subset of pavement drainage design on the performance of curb-opening inlets on grade.

Unique Clogging factors can be specified for inlets containing a curb opening or a grate, on grade or in a sag. These can be set and adjusted on the top Ribbon menu Inlet Design tab. Clogging factors are global in that they will be applied to all inlets in the project.

The standard inlets are the concrete gutter inlet, the Type B gutter inlet, the Type 12 combination inlet, and Type 22 curb inlets with lengths of 1.5 m, 3.0 m and 4.5 m. Model tests of these inlets on grade provided the relationships between captured discharge and total discharge for grades from 0.5% to 5.0% and cross-slopes of 1.6% and 3.1%.

A. Curb Opening Inlets on Grade (Type G-1). The capacity of a depressed curb inlet should be determined by use of Figures 4-10 and 4-11 in Appendix B of this Manual.

An economical design uses a minimum number of inlets by allowing the ponded width and depth to approach the allowable limits. In instances such as a narrow shoulders or low grades, there may need to be a continuous removal of flow from the surface.

An inlet on grade has a positive longitudinal gutter slope. Its interception capacity, Qi, is the flow intercepted by an inlet under a given set of conditions. The efficiency of an inlet, E, is the percent of total flow that the inlet will intercept for those conditions.

Sep 16, 2022 · A curb opening inlet located on grade behaves as a falling head weir. In order to determine the capacity of such an inlet, it is first necessary to determine the length of curb opening required to intercept 100 percent of the gutter flow.

In general, inlets are placed at all low points (sumps), along continuous grade curb and gutter, at median breaks, intersections and crosswalks. The spacing of inlets along a continuous grade segment of roadway is governed by the allowable spread of flow. See further details of allowable spread of flow in Chapter 7, Street Drainage.

Curb Inlet on Grade . Parent topic: Inlets on Grade ... Inlet Design Coefficients. Headloss Coefficients for Junctions; Roughness Values-Mannings Equation; Roughness Values-Kutters Equation; Mannings n Coefficients; Energy Cost Alternative. Bend Angle vs Bend Loss Curve. Hydrograph Curve Dialog Box.

Inlets on grade are located on a slope and intercept a portion of the water as it flows past. Inlets in sag are located at a point where runoff from a given area will ultimately collect, and these inlets are normally designed to capture 100% of the surface flow (otherwise, get flooding).

There are two major types of inlets approved for use within the County Right-of-Way, curb opening and grate. Inlets are further classified as being on a “continuous grade” or in a “sump”.

Curb Inlet on Grade . Parent topic: Inlets on Grade . Home > Theory > Surface ... Inlet Design Coefficients; SCS Peak Discharge. TR-55 Graphical Peak Discharge (SCS Graphical Peak) Initial Abstraction, Ia (in) Ia/P Ratio; Unit Discharge, qu (csm/in.) Runoff, Q (in.) Pond and Swamp Adjustment Factor;

This Technical Note addresses a subset of pavement drainage design on the performance of curb-opening inlets on grade.