JPH10280603A - Method of designing overhang length of all-weather berth overhung roof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of designing an overhang length of an all-weather berth overhung roof in accordance with the required operation rate of individual cargo handling facilities. SOLUTION: Actual data for wind speeds S(t0 ) and rainfall intensities W(t0 ) at individual times t0 are used to calculate the amount of rainfall W'(t0 ) entering a working area at the overhang length L of an overhung roof, assuming that it is L0 , from weather data for one or more past year at a planned all-weather berth installation place and compare it with an upper limit value for the amont of rainfall, possible for cargo handling work, so that judgement that it is workable or not at a time t0 is made. If judgement that it is workable is made, judgement that it is workable in a time section including the time t0 is made. Similarly, a workable time in a specified period (t=t0 through tmax ) for at least one year is calculated and the total is divided by all time in the specified period to calculate an operation rate F0 . The L0 is gradually increased from an initial value 0 to calculate the operation rate F0 in sequence and the L0 value at the time when the required operation rate is Freq or more is employed as a value for an overhang length in design.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for designing the overhang length of an all-weather berth overhanging roof for protecting a work area where cargo is handled between a ship and a quay from rainfall.

[0002]

2. Description of the Related Art Generally, an all-weather berth is installed to prevent rainfall from entering a work area where cargo is handled between a ship and a wharf. The all-weather berth consists of a building on the wharf and an overhanging roof that extends over the ship to cover the entire work area that spans the wharf and the ship anchored beside the wharf. Consisting of

[0003] In particular, in the handling of wet casting products subject to restrictions on wetting, it is important to prevent rainfall from entering the hatch opening of the hold located at the edge of the work area.
If the rainfall in the work area exceeds the allowable limit,
You must stop cargo handling. Therefore, in order to secure the required occupancy rate of each facility, it is extremely important in planning and designing the facilities how long the overhanging roof for preventing rainfall intrusion should be extended. .

Conventionally, however, there has been no method of quantitatively designing the overhang length necessary to secure the required operation rate.
Therefore, the overhanging roof of the all-weather berth has to be either overhanging as long as allowed by the construction cost or providing a wall or shutter along the periphery of the overhanging roof. Excessive construction costs were inevitable.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for designing the overhang length of an all-weather berth overhanging roof according to the required operation rate of each cargo handling facility.

[0006]

According to the present invention, in order to achieve the above object, according to the present invention, the length of overhang of an all-weather berth overhanging roof for protecting a work area for cargo handling between a ship and land from rain is protected. (1) Assuming that L ₀ = 0, (2)
Overhang length L from working area edge to overhanging roof edge L =
Assuming that L _0, (3) is set to the time t = t _0, from the past of weather data for the (s1) all-weather berth installation planned site, time
the wind speed S (t ₀₎ and the rainfall intensity W (t ₀₎ were taken in t _0,
(s2) At the wind speed S (t ₀ ), the maximum drop velocity Vmax of the raindrop reaching from the edge of the overhanging roof to the edge of the work area is represented by the following equation: Vmax = H / L ₀ × S (t ₀ ) (Where H is the height of the overhanging roof based on the height of the work area edge), and (s3) From the known relationship between the raindrop diameter R and the raindrop falling velocity V, The maximum raindrop diameter Rmax corresponding to the maximum drop velocity Vmax is determined, and (s4) the rainfall intensity W
Using the known raindrop diameter distribution in the case of (t ₀ ), a ratio G of raindrops in which the raindrop diameter R is equal to or less than the maximum raindrop diameter Rmax is calculated,
(s5) From the rainfall intensity W (t ₀ ) and the ratio G, the amount of rain W ′ (t ₀ ) entering the work area is calculated by the following equation: W ′ (t ₀ ) = W (t ₀ ) × G · ... (S6) By comparing the intrusion rainfall W ′ (t ₀ ) with the rainfall upper limit Wmax at which cargo work can be performed, the time t =
determining whether the loading operation at t _0, the result was recorded along with said time division Δt as a determination result of whether the loading operation for the time segment Δt containing t _0, (4) at least a predetermined period over one year (t = T ₀ to t _max ), the above steps (s1) to (s6) are executed for all times t after t ₀ ,
(5) The operation rate F ₀ is calculated by dividing the total Δt of the time division Δt in which the cargo handling work can be performed as described above by the total time (t _max −t ₀ ) of the predetermined period, and (6) F ₀ is compared with the required operation rate Freq, and if F ₀ ≧ Freq, the overhang length L =
L ₀ is determined, and if F ₀ <Freq, the value of L ₀ is increased by a predetermined increment ΔL, and the above steps (2) to (6) are performed. An overhang length design method is provided.

[0007]

In the [embodiment of the present invention, from the weather data of at least the past year for the all-weather berth installation planned site, the individual time t ₀ in the period wind speed S (t ₀₎ and the rainfall intensity W (t ₀ ), the rainfall W ′ (t ₀ ) falling into the work area when the overhang length L of the overhanging roof is temporarily set to L ₀ is calculated, and this can be used for cargo handling work. compared to rainfall upper limit Wmax, determines whether the work at time t _0.

If the result of the determination is that work is possible, it is determined that work is possible for the time section Δt including the time t ₀ . For example,
Assuming that the time interval Δt = 1 hour, the time t = t ₀ to the time t
= One hour up to t ₀ +1 is defined as a workable time. In this way, a predetermined period (t = t _0-
t _max ), the workable time ΣΔt is calculated, and this ΣΔt
Is divided by the total time (t _max −t ₀ ) of the predetermined period, and the operation rate F ₀
Is calculated.

For example, the work determination result at t ₀ = 0: 00 on January 1, 1990 is the determination result for one hour from 0:00 to 1:00 on January 1, 1990, and t ₀ + 1 = Jan. 1990 The judgment result at 1:00 a.m. on January 1, 1990, 1
The determination result and the corresponding time section Δt (one hour in this example) are sequentially recorded over one year, such as making the determination result for one hour from hour to two o'clock.
If the predetermined period is one year, the final time t = t _max is 199
It will be 24:00 on December 31, 00:00. Next, the time divisions Δt (one hour each) determined to be operable are totaled and divided by the total time (24 hours × 365 days) of one year, which is a predetermined period, to obtain an operation rate F ₀ .

If the operation rate F ₀ is equal to or greater than the required operation rate Freq of the cargo handling equipment to be designed, the initially assumed overhang length L ₀ is determined as a design value. Actually, in the present invention, the design process is started with the initial value of the assumed value L ₀ of the overhang length L set to 0. For example, in Japan, there is no place where there is zero rainfall throughout the year, and if the overhang length L ₀ = 0, the result of frequent determination that work is impossible due to rain frequently appears, and operation throughout the year Rate F ₀
Should be very low and less than the required operating rate Freq. In that case, as defined in the step (6) of the present invention, the value of L ₀ is increased by a predetermined increment ΔL (for example, 1 m) without determining that the overhang length L = L _0, and Re-execute the above design process for L ₀ . Thus, L ₀
If sequential increases repeatedly executes design processes and the rain from entering the work area decreases successively operating rate F ₀ along with it so on are increased sequentially step upon reaching the required operating ratio Freq above (6 ) Stops the execution of the process,
The value of L ₀ assumed at that time is determined as the design value of the overhang length L. As is apparent from the above process, the overhang length L ₀ determined by this is the minimum value of the overhang length L required to secure the required operation rate Freq.

In the design method of the present invention, the wind speed, rainfall intensity, and raindrop diameter R obtained from past weather data are calculated.
The known knowledge of the known relationship between the rainfall velocity V and the raindrop diameter distribution for rainfall intensity W (t ₀ ) is used. These known findings include, for example, those listed below. As the wind speed and rainfall intensity from past weather data, hourly wind direction wind speed data and rainfall data in various parts of Japan published as AMeDAS data by the Japan Meteorological Association can be used. It is best if there is data on the site where the all-weather berth is to be installed, but in general, it is not always possible to obtain data on the site itself.

The raindrop diameter and the raindrop falling speed are described, for example, in Table 1 on page 10 of the Universal Encyclopedia 18 “Space and the Earth” (Shogakukan, published in July 1981). And terminal drop speed ”are available. The raindrop size distribution according to rainfall intensity is described in Meiji University Research Bulletin (Faculty of Science and Technology) No. 17, pp113-125, "Comparison of Millimeter Wave Attenuation by Difference in Raindrop Particle Size Distribution Formula" (by Seizuku Fukushi) Data is available.

The above specific example is used by the inventor of the present invention on the assumption that it is the best available range at the time of filing of the present application, and it is not necessary to limit the present invention to the above example in performing the method of the present invention. Of course, if better data is available, it is desirable to use it. Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of implementing the design method of the present invention will be described using virtual data. It is assumed that the wind speed S (t ₀ ) at time t ₀ obtained from AMeDAS data and the like and the rainfall intensity W (t ₀ ) are 5 mm / h at the installation site of the all-weather berth. At this time, in the all-weather berth shown in FIG. 1, assuming values of the overhanging roof height H = 13000 mm and the overhanging length L based on the edge B of the work area A straddling the pier P and the hold Q. L ₀ = 6200 mm. The lower the height H is, the harder it is for rain to fall. Therefore, it is desirable to set the height H as low as possible without taking into consideration the mast height of the ship and the operation of the crane.

The raindrops blown from the edge C of the overhanging roof travel along the trajectory shown by the broken line in FIG. Must be such that the raindrop falling speed is less than or equal to Vmax determined by the following equation. _{Vmax = H / L 0 × S} (t 0) ········ This is simply the geometrical relationships as understood from FIG. That is, the overhang length L ₀ (that is, the roof edge C
If it drops by the height H in a time that travels in the horizontal direction by a horizontal distance L ₀ ) from the to the working area edge B, the raindrop just reaches the working area edge B. Here, the horizontal speed of the raindrop can be considered to be equal to the wind speed S (t ₀ ). Therefore, if the falling speed (vertical speed) of the raindrop reaching the edge B is set as Vmax, the [vertical speed Vmax of the raindrop] / Horizontal speed S
(t ₀ )] must be equal to the ratio of [vertical traveling distance H / horizontal traveling distance L ₀ ]. That is, Vmax
/ S (t ₀ ) = H / L ₀ holds, and the above equation is derived.

By substituting the wind speed S (t ₀ ), the height H of the overhanging roof and the overhang length L ₀ into the equation, The maximum drop speed Vmax of raindrops entering the work area A is calculated as Vmax = 2.1 m / s.

FIG. 2 is a graph showing the relationship between the diameter of the raindrop and the falling speed. The curve shown in the figure is the aforementioned Encyclopedia of Encyclopedia 18 "Space and Earth" (Shogakukan, published in July 1981). )
10 is a regression curve based on the data described in “Size of raindrop and terminal drop velocity” in Table 1 of Table 10. From this regression curve, the raindrop diameter corresponding to the above Vmax is 0.51 mm
Is obtained.

FIG. 3 shows the rain intensity W (t ₀ ) = 5 mm / h
This is a graph showing the raindrop size distribution in the case of rainfall, and the previous bulletin of the Meisei University (Faculty of Science and Technology) No.17, pp113-125, "Comparison of Millimeter Wave Attenuation by Difference in Raindrop Particle Size Distribution Formula" (by Fukushi Kiyozo) )
Is a transcript of a part of the raindrop diameter distribution for various rainfall intensities described in the above section. The total area under this distribution curve corresponds to the total rainfall of the rainfall intensity W (t ₀ ) = 5 mm / h, and the area of the hatched portion with a raindrop diameter of 0.51 mm or less is
This corresponds to the rainfall W ′ (t ₀ ) that enters the work area. When the total area under the distribution curve is 100%, the ratio G of the area of the hatched portion is calculated to be 14%.

Therefore, the amount of rain W '(t ₀ ) that enters the work area is obtained as follows. This is compared with the upper limit of rainfall Wmax for cargo handling,
And determines whether the cargo handling operation at time t = t _0. In the present embodiment, the rainfall upper limit value Wmax = 1 mm / h, and it was determined that work was possible when the intrusion rainfall W ′ (t ₀ ) = 0.7 mm / h. Since AMEDAS data utilized in this embodiment is data of every 1 hour was determined to be working for the time segment from time t ₀ to time t ₀ +1 h (Delta] t = 1 hour).

The rainfall upper limit value Wmax is set as a wetting limit for determining whether or not the worker feels uncomfortable or affecting the product. In general, if the rainfall is 1 mm / h or less, the rainfall is so low that the worker does not notice that it is raining unless he is careful, and the work floor is wet or not wet. In this manner, the determination process is repeatedly executed in the same manner as described above for a predetermined period (t = t ₀ to t _max ) of at least one year, and the total ΣΔt of the time sections Δt determined to be operable is calculated over the entire predetermined period The operating rate F ₀ is calculated by dividing by the time (t _max −t ₀ ), and it is compared with the required operating rate Freq, and the assumed value L ₀ of the overhang length L =
Judge the right or wrong of 6200mm.

In this embodiment, for convenience of explanation, L₀= 620
0 mm, but in the actual design process, L₀
= 0 as an initial value to start the design process,
₀Increase the value and repeat the execution, F₀And Freq
Small relation is F₀<Freq to F ₀≧ Freq
Assumption L of L₀Is adopted as a design value of the overhang length L.

[0022]

As described above, according to the present invention,
The overhang length of the all-weather berth overhanging roof can be designed according to the required operation rate of each cargo handling equipment.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an all-weather berth to be designed according to the present invention.

FIG. 2 is a graph showing a relationship between a raindrop diameter and a raindrop falling speed.

FIG. 3 is a graph showing the distribution of raindrop diameters.

[Explanation of symbols]

H ... edge edge C ... overhanging roof assumptions A ... loading operation area B ... work area A of the overhang length L ₀ ... L of the height L ... overhang roof overhang roof

Claims (1)

[Claims] 1. A method for designing an overhang length of an all-weather berth overhanging roof that protects a work area for cargo handling between a ship and land from rainfall, (1) Assuming that L ₀ = 0, (2) ) assumes that Zhang Decho of L = L ₀ up to the overhanging roof edge from the work area edge, (3) set to the time t = t _0, of the past for the (s1) all-weather berth installation planned site from weather data, wind speed S (t ₀₎ at time t ₀ and the rainfall intensity W (t
₀₎ was collected, (s2) the wind speed S (t ₀ the maximum falling speed Vmax raindrop arriving from overhanging roof edge to the working area edge in), the following _{equation: Vmax = H / L 0 ×} S ( t ₀ ) (where H is the height of the overhanging roof based on the height of the working area edge), and (s3) between the raindrop diameter R and the raindrop falling velocity V From the known relationship, the maximum raindrop diameter Rma corresponding to the maximum drop velocity Vmax
seeking x, (s4) using known raindrop size distribution in the case of the rain rate W (t _0), raindrop diameter R calculates the ratio G of raindrops is less than the maximum raindrop diameter Rmax, (s5) From the rainfall intensity W (t ₀ ) and the ratio G, the amount of rain W ′ (t ₀ ) entering the work area is calculated by the following equation: W ′ (t ₀ ) = W (t ₀ ) × G calculated by ..., the by comparing the loading operation possible rain upper limit Wmax, it determines whether the cargo handling operation at the time t = t _0, the result (s6) the intrusion rainfall W '(t ₀₎ Time interval Δt including t ₀
Is recorded together with the time section Δt as a result of the determination as to whether the cargo handling work is possible or not, and (4) a predetermined period (t = t _0-
t _max) for all times t later than t ₀ in run the step (s1) ~ (s6), (5) or by the predetermined period totals sigma t of cargo handling possible time division Δt determined Is divided by the total time (t _max −t ₀ ) to calculate the operating rate F _0. (6) Compare the operating rate F ₀ with the required operating rate Freq, and if F ₀ ≧ Freq, the overhang length It is determined that L = L _0, and if F ₀ <Freq, the value of L ₀ is increased by a predetermined increment ΔL, and the above-mentioned steps (2) to (6) are performed. How to design the overhang length of the roof.