waterway engineeringwaterway engineering chapter 8

1、Chapter 88.1 general8.2 maneuvering lane8.3 ship clearance8.4 bank clearance8.5 channel types8.6 preliminary design guidelines for straightsegments8.7 preliminary design guidelines for straight segments8.8 channel width final design8.1 generalChannel widths should be designed to provide for the safe

2、 and efficient movement of vessels that are expected to use the channel.Width of the channel is measured at the bottom of the slope at the design depth.8.1 generalThe elements of channel width analysis are shown in Figure 8-1.8.1 general8.2 maneuvering laneThe maneuvering lane is that portion of the

3、 channel width within which the vessel might deviate from a straight line without encroaching on the safe bank clearance or entering a zone that would cause danger to passing ships.8.3 ship clearanceTo avoid interference and danger of collision, a clearance lane is needed between maneuvering lanes f

4、or channels designed for two-way traffic.8.4 bank clearanceBank clearance is the horizontal distance between the adjacent maneuvering lane edge and the bottom of the channel side slopes.8.5 channel typesTwo-way traffic channels allow free movement of vessels. Figure 8-2 shows an example of a two-way

5、 traffic channel.8.5 channel typesOne-way traffic channel segments are used where excavation of a larger channel would be very expensive or traffic volume is low. Figure 8-3 shows a one-way traffic channel.8.6 preliminary design guidelines forstraightsegmentsSome recent work by the Corps (2nd Ed of

6、EM 1112-1613, 2002, Draft awaiting publication) using information generated from ship simulation studies suggested the minimum channel widths presented in Table 8-2. The canal- and trench-type channels are shown in Figure 8-4.8.6 preliminary design guidelines forstraightsegmentsA third set of values

7、 for channel-width selection is presented in PIANC report “Approach Channels, A Guide for Design Supplement to Bulletin No. 95, June 1997 (see Table 8-3).8.7 preliminary design guidelines forstraight segments8.7.1 GeneralThe width of the swept path is dependent on the following factors: Ship yaw ang

8、le when turningLength and beam of the ship Ship rudder angleLocation and spacing of aids to navigation in the turnLocal current and other environmental conditions8.7.2 Channel Width in TurnsBecause the swept path of a ship making a turn is wider than its path in a straight channel reach, a greater channel width is required in turns and bends.8.7.3 Turn DesignThe increase in channel turn width shown in Table 8-8 can be designed in several ways.8.8 channel width final designThree scenarios were tested:1. Existing conditions: 400 ft wide 40 ft deep for model validation2. Phase I: 530