学術論文等の公表実績

〈学術論文等の公表実績〉
目
次
論文①：土木学会論文集 B1(水工学),Vol.70,No.2,pp.49-59,2014.
題名：新しい雨水吐室における流水分派の技術理論と検証
研究者：小田收平小田耕平荒尾慎司
＜第 59 回水工学講演会，早稲田大学，2015.3.11 ＞---------論文①の学会講演
題名：新しい雨水吐室における流水分派の技術理論と検証
研究者：小田收平小田耕平荒尾慎司
論文②：13thInternational Conference on Urban Drainage,Sarawak,Malaysia,7-12 September 2014.
題名：Study on Optimization of Combined Sewer System with New Diversion Chamber
研究者：Shuhei ODA, Kohei ODA, Shinji ARAO
論文③：第 52 回下水道研究発表会 N2-2-5，（2015/07/29）
題名：新しい分水施設の遮集特性に関する検証実験
研究者：荒尾慎司小田收平小田耕平
論文④：第 52 回下水道研究発表会 N2-2-4，（2015/07/29）
題名：確実な下水量制御での合流式下水道の改善提案
研究者：小田收平小田耕平荒尾慎司
論文⑤：下水道協会学術論文 Vol.52,No.634,2015.8.
題名：新しい雨水吐き室の遮集特性に関する実験的研究
研究者：荒尾慎司小田收平小田耕平
論文⑥：環境浄化技術 Vol.15,No.2,pp,79-83,2016.3-4.
題名：確実な下水道管理を可能にする新しい分水技術
研究者：荒尾慎司小田收平小田耕平
論文⑦：土木学会論文集 B1(水工学) Vol.72,No.4,I_583-I_588,2016.
題名：豪雨時でも遮集量を制御できる雨水吐室に関する研究
研究者：荒尾慎司長岡隆浩加田真依田上藍
中村公亮小田收平小田耕平
＜第 60 回水工学講演会，東北工業大学，2016.3.15
＞-------論文⑦の学会講演
題名：豪雨時でも遮集量を制御できる雨水吐室に関する研究
研究者：荒尾慎司小田收平小田耕平
論文⑧：第 53 回下水道研究発表会 N2-2-4，（2016/07/27）
題名：雨水対策で効果的な分水施設機能の改善
研究者：小田收平小田耕平荒尾慎司
論文 ① ， 1/11
1
2
1, 2
E-mail: [email protected]
3
3
160-0022
[email protected]
1-34-11
690-8518
E-mail: [email protected]
14-4
1
45%
3%
Key Words : combined sewer system, diversion chamber, intercepting problem
1
(1)
100V
200V
-1
1 , 2
Qi
-2
3
Q2
3
Q1
1 3
4
-2
-1
論文 ① ， 2/11
(2)
C2
m2
0.6
a
m
h
1.3
C2
h
0.6
C2
7
5
8
6
0.6
C2
(2)
a)
2
Q1
3/2
1.8
(1)
Q2
1/2
2g
Q1
1/2
2.66
Q2
-3
5
3
Q1 m /s
6
1
b)
Q1
C1 B H
3/2
(1)
1.8
C1
m
m
H
1/20
C2 a
2 g h
B
W
1/100
Q2 m3/s
Q2
-2
1/ 2
2
(2)
-4
0.350 m
1.5 m
B3 = 7.0 m
WL
B2 = 3.0 m B1 = 3.0 m
WL
WL
-3
-4
3
0.2365+0.0122 1/2
0.2365 1/2
=1.025
2.5%
論文 ① ， 3/11
Q2)
2
3
h0
Q0)
1
(1)
a)
3
2
5
Q2
Q1
-6
Qi
1
b)
-5
4
Q2
1
%
5
Qi
1/2
71%
Q2 Q0
Q0
(5)
100
4
(4)
Q0
-1
9
c)
10
3
3
3
Qi m /s
Q1 m /s
20
100
50
Q2 m3/s
Qi
Q1
(3)
Q2
(2)
-5
1
m
1
2
3
4
1
0.35 m 0.286 m
20%
1
2
1
0.286 m
1/40 4
1/110
3
0.35 m
0.247 m
1/2
1/10 3
97%
1/109 1/145
1/41 1/52
1/10 1/12
1,000
4
3
(11) (9) (8)
(12)
(10)
(7)
200
(6) (5)
(4)
(3)
(1)
(2)
1/1.4
100
1
2
50
1/41
2/3
0.247 m
1/1.2
1/10
13.00 m
6.50 m
4.33 m
3.25 m
2
3
4
1/2
1/1.2
-1
10
1/1.6
1/1.5
1
0.01
1
0.1
1/1.2
1/1.4
10
100
Q2-Q0
-5
1/1.6
5
1,000 (%)
Q0 ×100
1/109
1/1.5
20
論文 ① ， 4/11
4
3
0.13 m
3
(1)
a)
3
-5
d)
-6
b)
3
13 m
-1
0.35 m
-6
1
0.35 m
0.01 m
4.33 m
0.35 m
3
(2)
c)
a)
7
-6
0.39 m
5
1/33
-7
( )
1,000
0.020 m
0.015 m
0.350 m
0.010 m
0.0075 m
0.005 m
500
B0.130 m 3
B0.130 m 3
B4.33 m 3
B0.130 m 3
B0.130 m 3
B0.130 m 3
100
50
20
10
0.020 m
B0.390 m 1
0.015 m
B0.390 m 1
0.350 m
B13.0 m 1
0.010 m
B0.390 m 1
0.0075 m
B0.390 m 1
0.005 m
B0.390 m 1
5
1
0.01
0.1
1
10
(Q2-Q0)
-6
0.35 m
100
(Q0)×100
1,000(%)
論文 ① ， 5/11
20
0.39 m
1
0.01 m
1
0.13 m
0.01 m
3
3
1
2
3
1
0.013 m
2
3
1
-7
3
-3
-2
-2
b)
-3
Q2
1
3
3
2
1
0.01 m
(
)
0.01 m
(
3
2
1
-7
)
論文 ① ， 6/11
1
-2
Q1
(kg
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
13.0
13.8
12.0
11.8
16.0
11.0
17.5
12.0
10.6
6.0
12.0
12.0
13.2
7.0
13.5
14.3
11.0
6.8
16.7
12.5
16.9
13.9
26.8
23.8
27.0
29.5
16.6
24.0
20.2
27.8
17.8
29.2
30.8
(kg
20.8
21.2
19.0
20.0
31.0
27.0
32.0
28.0
17.8
14.2
19.0
20.2
19.9
15.2
20.5
21.4
27.2
23.2
32.6
28.6
33.5
30.2
(
(/ )
(kg
(kg
(
1.00
1.00
1.00
1.00
4.60
4.60
4.58
4.59
120
120
120
120
0.03000
0.03000
0.02983
0.02992
0.0299=Q0
1.5200
1.50
4.00
60
0.0417
1.5617
52.23
39.46
39.0
10
1.5200
1.50
4.40
60
0.0483
1.5683
52.45
61.54
58.0
20
1.5500
4.40
6.95
60
0.0425
1.5925
53.26
42.14
60.0
20
1.5250
2.65
5.35
60
0.0450
1.5700
52.51
50.50
32.0
20
0.7700
7.05
9.30
60
0.0375
0.8075
27.01
25.42
39.2
20
0.7600
3.15
5.38
60
0.0372
0.7972
26.66
24.41
35.1
20
0.7450
1.90
4.20
60
0.0383
0.7833
26.20
28.09
41.9
20
0.7050
2.10
4.30
60
0.0367
0.7417
24.81
22.74
,
50.4
60
0.5433
1.20
3.30
60
0.0350
0.5783
19.34
17.06
,
61.2
60
0.5333
6.15
8.25
60
0.0350
0.5683
19.01
17.06
63.7
60
0.5483
4.50
6.70
60
0.0367
0.5850
19.57
22.74
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
32.3
26.0
32.8
21.0
27.5
20.8
20.2
17.6
18.7
18.8
17.8
18.4
(kg
34.0
36.0
29.5
32.5
34.0
34.9
27.0
29.8
29.8
31.0
24.1
25.0
16.8
19.0
15.7
17.5
16.2
17.8
16.0
18.1
11.2
12.9
11.6
13.0
( / ) Qi=Q1+Q2 Qi /Q0 (Q2-Q0)/Q0
10
( )
Q2
(
2
1
3
Q1
14.8
17.5
11.0
15.0
15.0
17.8
9.0
12.0
12.5
15.0
9.6
11.2
9.0
11.2
7.8
9.8
8.7
10.0
8.0
10.8
7.8
10.0
8.5
9.9
(%)
42.0
-3
(kg
( )
Q2
(/ )
(kg
(kg
(
3.90
1.30
3.50
1.00
5.65
3.06
5.22
2.73
60
60
60
60
0.02917
0.02933
0.02867
0.02883
0.0290=Q0
(%)
( / ) Qi=Q1+Q2 Qi /Q0 (Q2-Q0)/Q0
70.0
20
1.8850
4.80
6.58
60
0.0297
1.9147
66.02
2.41
62.0
20
1.8000
4.40
6.20
60
0.0300
1.8300
63.10
3.45
68.9
20
1.8050
2.20
3.98
60
0.0297
1.8347
63.27
2.41
56.8
20
1.7900
2.50
4.27
60
0.0295
1.8195
62.74
1.72
60.8
20
1.6650
5.40
7.18
60
0.0297
1.6947
58.44
2.41
49.1
20
1.4150
3.20
5.00
60
0.0300
1.4450
49.83
3.45
35.8
20
0.7800
3.20
4.98
60
0.0297
0.8097
27.92
2.41
33.2
20
0.7800
2.45
4.23
60
0.0297
0.8097
27.92
2.41
34.0
20
0.7650
3.90
5.68
60
0.0297
0.7947
27.40
2.41
34.1
20
0.7650
3.17
4.97
60
0.0300
0.7950
27.41
3.45
24.1
20
0.3150
2.05
3.84
60
0.0298
0.3448
11.89
2.76
24.6
20
0.3100
1.50
3.28
60
0.0297
0.3397
11.71
2.41
2
,1
1
,
論文 ① ， 7/11
(3)
-6
-2,
-3
-8
-8
1
a)
3
-8
C1 C2
b)
50
-1
-4
-5
Q0
Qa
3
3Qa
6Qa
66
-8
1
32
50
50
-8
3
2.4%
1
45%
3.4%
3
3%
15
200 ( )
3
(B0.13 m× 0.01 m)×3
1
(B0.39 m× 0.01 m)×1
3
(B4.33 m× 0.35 m)×3
1
(B13 m× 0.35 m)×1
100
90
80
1/15
70
(4)
60
(1)
(3)
(5)
(2)
(3)
(1)
(6)
50
2.6
40
30
(7)
(8)
(9)
3%
1
B0.39 m× 0.01 m ×1
3
B0.13 m× 0.01 m ×3
(10)
20
45%
(5)
(6)
(8) (7)
(9)
(10) (11)
(11)
10
(2)
(4)
0.1
1
0.5
(12)
5
Q2-Q0
-8
50
10
Q0 ×100
100 (%)
論文 ① ， 8/11
5
(2)
1
(1) 3
(2)
(1)
K
Y
3
-5
-9
-10
-4
-7
-4
-5
Qa= 0.0200 m3/s
Q0= 0.1243 m3/s 6.215 Qa 2
Qr= 3.9153 m3/s
1/3
Qmax= 3.9353 m3/s
Q0 50%
2
Q0= 3 Qa
Q0= 6.2 Qa
B
B13 m× 0.35 m×1
B13 m× 0.286 m×1
B20 m× 0.35 m×1
B(3+3+7)m× 0.35 m×3
3
66
32
A 1
A 2
B
B-B
A-A
B
3
A
A
3
3
B
A-1
0.35 m
3
3
0.286 m
13 m
20 m
A-2
3
A-1,2
-9
1
B
A-A
B-B
A
B
-10
B
3
A
論文 ① ， 9/11
(3)
-6
a)
3
-5
Q2
Q0
-11
Qi , m a x Q1 Q2
Q1
-12
1,000( )
A-1
1/20
1/2
500
A-2
1/1.26
B
200
24.86 m3/s
100
12.43 m 3/s
50
6.215 m3/s
31.66
101.5(12.62 m3/s)
3.2 max
48.1(5.98 m3/s)
1.5 max
3
Qmax=3.9353 m /s
20
2.486 m3/s
10
1.243 m3/s
5
0.6215 m3/s
1/10
1
24.9%
39.2%
49.8%
A-2
1
0.1
A-1
B
2.5%
50%
1/16
10
1,000 (%)
100
(Q2-Q0)
(Q0)×100
-11
0.4444 m
0.2966 m A-1
0.2219 m A-2
-12
B (3+3+7)m× 0.35 m×3
3m
( 1 )
B
3m
( 2 )
0.2365 m A-2
B
7m
( 3 )
B20 m× 0.35 m×1
0.5306 m A-1
A-2
0.0122 m
B13 m× 0.286 m×1
0.0539 m
A-1
論文 ① ，10/11
-6
0.286 m
a=0.064242 m2
Q0= 0.6 0.064242 (2 9.8 0.5306)1/2
= 0.124303 m3/s
Q0
OK
Q1 Q2= 1.8 13 0.29663/2 0.6
0.064242 {2 9.8 (0.5306 0.2966)}1/2
= 3.779833 0.155204
= 3.93504 m3/s
Qmax
OK
B
10
B1=13 m
h0=0.5306 m
A-1
H1=0.2966 m
Q2/ Q0
0.35 m
a=0.096211 m2
0.155204 0.124303=1.2486
25%
Q0= 0.6 0.096211 (2 9.8 0.2365)1/2
= 0.124285 m3/s
Q0
OK
Q1 Q2= 1.8 20 0.22193/2 0.6
0.096211 {2 9.8 (0.2365 0.2219)}1/2
= 3.76304 0.17303
= 3.93607 m3/s
Qmax
OK
B
16
B1=20 m
h0=0.2365 m
A-2
H1=0.2219 m
Q2/ Q0
a=0.09621 m2
39%
0.35 m
B1=3 m
B2=3 m
B3=7 m
h0=0.2365 m
B
0.17303 0.124285=1.3922
H1=0.0122 m
H2=0.0539 m
H3=0.4444 m
Q0= 0.6 0.09621 (2 9.8 0.2365)1/2
= 0.124285 m3/s
Q0
OK
Q1 Q2= 1.8 (3 0.01223/2 3 0.05393/2
7 0.44443/2) 0.6 0.09621
{2 9.8 (0.2365 0.0122)}1/2
= 3.80762 0.12745
= 3.93507 m3/s
Qmax
OK
Q2/ Q0
2.5%
0.12745 0.124285=1.02547
b)
-7
-7
A-1
A-2
25%
1/3
50%
3.2
A-1,2
B
A-2
B
39%
50%
2.5%
50%
1.5
1.5
/
(94%)
2.1
/
(131%) 1.6
/
(100%)
9.7
/
(139%) 19.4
/
(277%) 7.0
/
(100%)
11.2
/
(130%) 21.5
/
(250%) 8.6
/
(100%)
A-1
/
B
,
/
4
4
6
(2)
論文 ① ，11/11
6.
(1)
1
40
15
3
1)
2)
( )
pp.106-119, 259-262, 2010.1.
( )
3)
( )
pp. 7-13, 2003.3.
pp. 122-123, 153-161, 163, 2002.6.
4)
SPIRIT21
2004.6.
( )
8
5)
6)
( )
85-92, 2002.10.
( )
pp. 18-19, 2007.3.
7)
pp.
( ),
(
), pp. 197-208,
1978.3.
(2)
pp. 190-199,
8)
1962.7.
9)
http://www.gesui.metro.tokyo.jp/oshi/infn0765/siryou_076
5.pdf
10)
pp. 6-7, 2012.11.
2013. 10. 21
TECHNICAL THEORY AND VERIFICATION OF FLOWING WATER
DIVERSION IN NEW RAINWATER DISCHARGE CHAMBER
Shuhei ODA, Kohei ODA and Shinji ARAO
The combined sewer improvement works addressed in sewer advanced areas have had a task in the
interception accuracy of sewerage flowing into an intercepting pipe, and its countermeasures have also
been pointed out in terms of a low improvement effect and complicated maintenance and management.
With regard to the flowing water diversion function, a hydraulic phenomenon of an overflow weir and an
orifice is organically combined, and in the conventional technology, flow quantity is directly controlled
by overflow in a single tank, but this study proposed an indirect control with several tanks to regulate the
water level in the diversion chamber. This study was to verify technical theories of the conventional
technology and the new technology with regard to the interception accuracy of sewerage flowing into the
intercepting pipe, and scrutinized data of a numerical analysis of a diversion phenomenon and a hydraulic
model experiment to judge the validity from a management practice point of view. Results of this study
showed that an excessive interception error of sewerage by the conventional technology, 45% become to
3% or less by the new technology with three regulating tanks in the diversion chamber.
論文 ② ，1/8
13th International Conference on Urban Drainage, Sarawak, Malaysia, 7 12 September 2014
Study on Optimisation of Combined Sewer System with New
Diversion Chamber
ShuheiODA1, Kohei ODA1*, Shinji ARAO2
1
2
Waken Design Office Inc., 34-11 Shinjuku 1-chome, Shinjuku-ku, Tokyo 160-0022, Japan
Department of Civil and Environmental Engineering, Matsue College of Technology, 14-4
Nishi-ikuma, Matsue 690-8518, Japan
*Corresponding author
Email:[email protected]
ABSTRACT
Conventional combined sewer systems achieve certain environmental improvement by quick
and efficient equipment investment though there are difficulties in reliable sewage
management. In this study, a new diversion chamber has been developed, and an optimization
theory, allowing the most effective environmental project investment, has been built by
incorporation of the new equipment into the combined sewer system. Numerical analysis,
hydraulic model experiments and schematic design of a sewer project cases how that the new
equipment provides a solution to issues associated with conventional sewer management and
a high return on investment in environmental improvement.
The outcomes of this study can be applied in developing countries by collaborative
technology transfer coordinated with the circumstances of the country concerned, so as to
construct a project development framework based on autonomy and independence.
KEYWORDS
Combined sewer, diversion chamber, interception accuracy, optimisation, pollutant reduction
INTRODUCTION
The objectives of the Japanese project to improve combined sewer systems are
twofold.Theimmediate objectives are pollution load reduction, security of public sanitation,
and reduction of impurities. The long-term objectives are to find solutionsto the problems of
non-point pollution and untreated watereffluent.Similar challenges occur worldwide.
In the conventional combined sewer system whereintercepting and overflow of sewageare
incorporated inadiversion chamber, the interceptionaccuracyin the chamberislowduring
periods of heavy rainfall, and so it is difficult to achieve reliable sewage management. To
meet the objectives outlined above, a major challenge is to develop equipment to achieve
higher diversion chamber function effectiveness and a rational sewer systemfor quantitatively
grasping the effects of improvement project investment (JSWA, 2002; MLIT, 2002).
The objectives of this study are to develop a new diversion chamber and to create a combined
sewersystemfor quantitatively grasping the effects of investing in an environmental
improvement project through reliable sewage management. The approach is to construct a
sewer system theory based ona combination of published data on technologies,management
information accumulated during sewer improvement projects in Japan, and widely-used
industrial knowledge. Then to transfer, through collaboration with developing countries, a
technology that could be adjusted to reflect site conditions and that would allow the country
concerned to achieve autonomy and independence.
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13th International Conference on Urban Drainage, Sarawak, Malaysia, 7-12 September 2014
IMPROVEMENT OF INTERCEPTION ACCURACY IN DIVERSION
CHAMBER
Problems with the intercepting function of diversion chambers
A standard mechanism for intercepting and overflow of sewage flowing into the diversion
chamber is shown in Fig. 1 (JSWA, 2010; JIWET, 2003;Giudiceet al.,1999; Hager, 1999;
Mays, 2001).Conventional improvement measures are illustrated in Fig.2 (JSWA, 2002). The
mechanism is configured to directly control and maintain a target flow rate by regulating the
sewageflowing into an intercepting pipe and to enhance the function of the overflow weir. In
the conventional technology, overflow and intercepting are controlled by a single mechanism,
and so is inevitably accompanied by an increase in water rising in the regulating tank. The
result is that the flow rateofinterceptedsewageincreases(Fig. 3;JSWA, 2002) and the
combined sewer system collapseswhenrainfallis heavier than predicted. This causes sewage
management problems such as intercepting and combining flow and discharge of untreated
effluent.
Orifice type
Overflow weir
Pole-shaped control board
(with built-in hydraulic powerunit)
Inflowflow rate, Qi
Combined sewer
Vortex valve type
Combined
sewer
Intercepting
pipe
Combined
sewer
Manhole
Electric piping
Water-level gauge
Filtering screen
+ overflow weir
Falling water division type
Intercepting
pipe
Overflow weir
Opening
Combined
sewer
Overflow
outlet
Overflow
outlet
GL
i i
Vortex
Orifice
Opening
Intercepting
pipe
Overflow
outlet
Figure 2.Improvement measure forinterceptedsewageeffluent
(plan view)
Conventional technology
Excessive
flow
excessive interception
rateofintercepted
(Q c Q o)
sewage
(Q Q )
Intercepting pipe
Orifice flow rate
New technology
Overflow outlet pipe
Planned flow rateofintercepted sewage(Q 0)
Overflowflow rate
Overflow start time
Planned rainfall duration Inflow flow rate (Qi)
Figure 1.Standard diversion equipmentFigure3.Problems resulting from excessive flow rate
of intercepted sewage
Basic theory of flowing water indiversion chamber
In this study,as shown in Fig. 4, the basic theory of flowing waterin a diversion chamber is
utilization of combination of hydraulic phenomena of an overflow weir and an
orifice.Theflowratesatan overflow weir and an orifice are calculated by Equations (1) and (2)
respectively.
Q1=C1Bh3/2(1)
whereQ1: the overflow flow rateat the weir (m3/s), C1: thedischargecoefficient (= 1.8), B:
theoverflow weir width (m), h: the overflow water depth (m), and W: the overflow weir crest
height (m).
Q2=C2a(2gh)1/2 (2)
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13th International Conference on Urban Drainage, Sarawak, Malaysia, 7 12 September 2014
whereQ2: the flow rate at the orifice (m3/s), C2: thedischargecoefficient (= 0.6), a: theorifice
hole area (m2), h: thehead difference (m), and g: the gravitational acceleration (m/s2).
Figure4. Schematic view of overflow weir and orifice
Interceptinganddiversiontheory for inflow sewage and improvement measures
The increase in flow rate of inflow sewage is accompanied by an increase in water rising in
the regulating tank of the diversion chamber. As expressed by Equations (1) and(2),for the
same increase inwaterdepth,theincrease in flow rate at the orifice is extremely small when
compared with the increase in flow rate at the overflow weir. The basis of the intercepting and
overflow theory applied to the new diversion chamber is utilization of one set of hydraulic
phenomena at the orifice and overflow weir.
The conventional improvement measure for the intercepting and diversion function isdirect
control of the target flow rate by one set of apparatus as illustrated in Fig. 5, and thus there is
a large interception error (Equation (4)) in terms of hydraulics. As shown in the figure, an
improvement measure for a new diversion chamber proposed in this study istoprovide a
pluralityof sets of combinations of an overflow weir and an orifice. The new technology is an
indirect method of effectively controlling the target flow rate by sequentially controlling the
water levels in regulating tanks on a tank-by-tank basis to fix the water level in the final
regulating tank, thus providing significant improvement in performance of the system as a
whole.
Single regulating tank with orifice holeareathrottled to 2/3
Inflow pipe 1.5
m
B = 13.0m
Three regulating tanks withorifices
m
Orifice 0.286
(Throttling 67%)
B3 = 7.0 m
WL
( 0.5306+0.2966)
Orifice 0.350 m
Inflow pipe 1.5 m
B2 = 3.0 m B1 = 3.0 m
WL
1/2
0. 530 6 1 / 2
=1.25
error 25%
( 0.2365+0.0122) 1/2
WL
WL
0.2365 1/2
=1.025
error 2.5%
a)Conventional technology
b)New technology
Figure5.Conventional technologyand new technology (side view)
Verification of the interceptingand diversion theory
The item to be verified is the interception error for the flow rateinthe intercepting pipe.A
hydraulic phenomenon is specified from a theoretical solution using numerical analysis in a
verification model and confirmed in a hydraulic model experiment of a representative
model.The verification models are one set of intercepting and overflowequipment,which is the
conventional technology, and a plurality of sets of intercepting and overflow equipment which
is proposed as the new technology. A comparison of the scale in each model is listed in Table
1.
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13th International Conference on Urban Drainage, Sarawak, Malaysia, 7-12 September 2014
Table 1.Scale oftheconventional technology and the new technology
Verification of the proposedtechnology is madeby dimensionless Equations (3) and (4), and is
evaluated in a general range of a sewage flow rate ratio, Qi/Q0.
Sewage flow rate ratio (times) = Qi/Q0
(3)
Interception error (%) = {(Q2 Q0)/Q0}×100
(4)
whereQi: the sewageflowrateinto the diversion chamber (m3/s), Q0: the plannedintercepting
flow rate (m3/s),and Q2: the intercepting flow rate (m3/s).
The numerical analysis results and hydraulic model experiment results are given in Figures 6
and 7. The sewage flow rate ratio, Qi/Q0is evaluated at an intermediate value of 50% of the
project plan range. As for the theoretical solution of the diversion chamber,
theinterceptionerror is improved to 1/1.2by throttling the orifice hole area to2/3 in the first
regulating tank (Fig. 6). Increasing the number of regulating tanks reduces
theinterceptionerror of the first regulating tank to 1/10in the second regulating tank, to 1/41in
the third regulating tank, and to 1/109 in the fourth regulating tank.
The results show that the higher interceptionaccuracy can be obtained with a larger number of
regulating tanks and a larger inflow flow rate, Qi, so that the theoretical curves in Fig. 6
become upright. As shown in Fig. 7, the hydraulic model experiment result in the single
regulating tank of the conventional technology is almost coincident with the theoretical curve.
The experiment resultsfor the three regulating tanks of the new technology are not completely
coincident with the theoretical curve. However, the curves become upright near
aninterceptionerror of about 3%, indicating a high improvement effect of about 1/15 of the
error of the single regulating tank. A reason whythe experiment result of the three regulating
tanks is not coincident with the theoretical curve is that thedischargecoefficients of the
overflow weir and the orifice are fixed in the numerical calculations.
Effect of providing a plurality
of regulating tanks
(times)
about 1/109
1/145
about 1/41
1,000
1/52
about1 /10 1/12
Fourth tank
4-S
200
Third tank
3-S
4-M
4-L
2-S
3-L
3-M
100
Second tank
2-L
First tank
Analytical results showing improvement
in system performance
1-S
1-L
2-M
1-M
50
20
10
5
Orifice hole
throttling effect
1/1.6
1/1.5
1/1.4
1/1.2
1
0.01
0.1
1
10
100
1,000 (%)
{(Q2-Q0) /Q0}×100
Figure6.Improvement inintercepting control results fromnumerical analysis
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13th International Conference on Urban Drainage, Sarawak, Malaysia, 7 12 September 2014
(times)
200
100
90
80
70
60
Model size analysis data of 3 tanks
(B0.13m× 0.01 m)×3 tanks
Model size analysis data of 1 tank
(B0.39m× 0.01 m)×1 tank
Site size analysis data of 3 tanks
(B4.33m× 0.35 m)×3 tanks
Site size analysis data of 1 tank
(B13m× 0.35 m)×1 tank
almost1/15
2.6%
50
almost 3%
Model sizeexperimental data of 1 tank
(B0.39m× 0.01 m)×1 tank
Model sizeexperimental data of 3 tanks
(B0.13m× 0.01 m)×3 tanks
40
30
45%
20
(times)
10
0.1
0.2
0.3
0.4 0.5
1 (%)
2
3
4
5 6 7 8 9 10 (%)
20
30
(%)
40 50 60 70 80 90 100
{(Q2-Q0) /Q0}×100
Figure7.Comparison between numerical analysis and model experimental results
OPTIMIZATION OF THE COMBINED SEWER SYSTEM
Sewer systems in developing countries and application of the new technology
An important issue ofseweragedevelopment in developing countries is to resolve conflicting
problems such as limited investment and the need for urgent development. In considering
possible solutions it is most important to consider the expansibility of a target technology,
whether project management is based on autonomy and whether independence is possible.
Focusing on collaboration is also veryimportant.The sewer system utilizing the new
technology manages sewage by a reliable diversion function and retention of the intercepted
sewage in a reservoir of a predetermined scale. In addition, this system plans for the
distribution of an appropriate sewageamountandfacilityarrangement, and specifies the most
effective improvement system in a combined sewer by demonstrating the effects of
investment in the environmental project.Thereby,the system appropriately rationalizes project
management through significant project cost reduction and simple facility management.
A schematic design is made using a project case as a reference model, and improvement
effects of the sewer system utilizing the new technology are organized below.Plan conditions
in the schematic design are listed in Table 2.
Table 2. Specifications for verification case
Improvement effects and schematic design results of facility arrangement
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13th International Conference on Urban Drainage, Sarawak, Malaysia, 7-12 September 2014
The relation between numerical analysis results and facility schematic design results is
illustrated in Table 3, Table4 and Fig. 8.
Table 3.Schematic design results of sewer systems
: Partially satisfied,
: Moderately satisfied,
Figure.8Improvement effectsofnewtechnologyfor each target rainfall intensity
Table 4.Scale of diversion and dividingchambers
6
: Fully satisfied
論文 ② ，7/8
13th International Conference on Urban Drainage, Sarawak, Malaysia, 7 12 September 2014
Diversion chamber
Dividing chamber
Conventional technology
Plan
1 regulating tank (B24 m, 0.35 m)
With no chamber
Plan A
3 regulating tanks (B3 m, 3 m and 7 m, 0.35 m)
3 regulating tanks (B3 m, 3 m and 5 m, 0.35 m)
New technology
Plan B
Plan C
B
3 regulating tanks (B3 m, 3 m and 5 m, 0.25 m)
B
3 regulating tanks (B3 m, 3 m and 5 m, 0.15 m)
3 regulating tanks ( 3 m, 3 m and 7 m, 0.35 m)
3 regulating tanks ( 3 m, 3 m and 7 m, 0.35 m)
Flow rate distribution of the combined sewer system and the facility arrangement plan
The sewage flow rate distributions and the facility arrangements of the conventional
technology and the new technology,planC are illustrated in Fig. 9 and Fig. 10, respectively.
Figure9. Analysis of combined sewer system using conventional technology
Figure10.Analysis of optimizedsewersystem usingnew technology (plan C)
Comparing the effects of improvement of the diversion chambers by the conventional
technology and the new technology, the conventional technology has an interceptionerror of
as large as 59% (Table 3) and thus can be expected to create difficulties for reliable sewage
management since it cannot resolve the issues such as intercepting and combining flow, or
preventing discharge of untreatedeffluent during heavy rainfallevents.Conversely, the new
technology has an interception error of 1% or less and sowill allow reliable sewage
management. This can solve both the current issues in the combined sewer improvement
project and future environmental issues.
In the conventional technology, bothsimply treated sewageanduntreated sewageflow into the
public water areasas shown in Fig. 9, causing environmental degradation.However, as shown
in Fig. 10,by expanding the reservoir capacity by 52%for the new system (plan C) with the
proposed diversion chamber, only the highly treated sewage is discharged into the public
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論文 ② ，8/8
13th International Conference on Urban Drainage, Sarawak, Malaysia, 7-12 September 2014
water areas.If the sewerage network system is optimized by utilizing the new technology, only
completely treated water can be discharged, greatly improving the environment.
Comparing the project investment effects, this study has roomfor improvement in planning
for the futuresewageamountand facility arrangements.However, the proposed system can
achieve a hugecost reduction by complementing the investment on the expensive mechanical
and electrical equipment and complicated advanced maintenance and management in the
treatment plant, with the investment on the inexpensive facility allowing self-management
and simple maintenance and management.Therefore, utilization of this optimized system
suggests that an environmental project with both high transparency and high cost reduction
effectiveness is possible not only in developing countries, but also in developed countries.
CONCLUSIONS
In this study, a new diversion chamber with several regulating tanks was developed for a
combined sewer system.From both theanalytical and the experimental results, the new
technology has high interceptionaccuracy of the sewage flowing into the treatment facility
during periods of heavy rainfall. This study has also presentedthe case of combined sewer
system optimization,by providing effective project managementusingthe proposed diversion
chamber.Reliable sewage management can be achieved by quantifying the correlation
between the investment on the environmental project and the effects of the improvementsfrom
applying the technology.
Sewer development in developing countries requires urgent attention with only limited
investment funds. The system proposed in this study meets this requirement. To address the
problem of insufficient basic data on the sewer management in the developing countries, the
most suitable project operation is believed to bestepwise project investment in which sewer
developmentis advanced by utilizing basic data from Japan or from a similar basin in a
neighboring country. As data is accumulated over the yearsafterthefacility is put into service,
it will be possible to plan maintenance and perform necessary addition work.
REFERENCES
Giudice,G. D. and Hager, W. H. (1999). Sewer Sideweir with ThrottlingPipe, Journalof Irrigation and Drainage
Engineering, Vol. 125, No. 5, pp.298-306, September.
Hager, W. H. (1999).Wastewater Hydraulics, Theory and Practice,pp.513-566, Springer.
Japan Sewage Works Association (2002). Combined Sewage Improvement Measure Guideline and Explanation,
pp. 8-10, pp. 65-67, pp. 122-123, pp. 153-159, p. 163 (in Japanese).
Japan Sewage Works Association (2010).Exposition of Sewage Facility Plan and Design Policy, pp. 106-119,
pp. 259-262 (in Japanese).
Japan Institute of Wastewater Engineering and Technology (2003).Combined Sewer Improvement Measure
Filtering Screen Technical Manual, pp. 7-13 (in Japanese).
Mays, L. W. (2001) .Storm Water Collection Systems Design Handbook, pp.18.1-18.4, McGraw-Hill.
Sewerage and Waste Water Management Department of the City and Region Development Bureau in the
Ministry of Land, Infrastructure and Transport (2002). Investigation Report regarding Combined
Sewerage Improvement Measure, pp. I-23-I-30, pp. II-65-II-67, pp. II-130-II-147, pp. II-200-II-204 (in
Japanese).
8
論文 ② ，1/7
発展途上国での合流式下水道システムの最適化研究
小田
1,2
収平 1・小田耕平 2・荒尾
株式会社和建設計事務所（〒160-0022 東京都新宿区新宿 1-34-11）
E-mail: [email protected]
3
慎司 3
[email protected]
会員松江工業高等専門学校環境・建設工学科（〒690-8518 島根県松江市西生馬町 14-4）
E-mail: [email protected]
従来の合流式下水道システムは，迅速に効率的な設備投資で一定の環境改善を図るが，確実な下水道管理は困難であ
る．本研究は，新規に流水分派設備を開発して下水道管理を確実にし, この設備を合流式下水道システムに取込み最も効
果的な環境事業投資となる下水道システムの最適化理論に発展させ，理論解の数値解析，水理現象把握の水理模型実験，
下水道事業事例の概略設計で従来の下水道管理での課題解決と環境改善での非常に高い投資効果を立証した．
発展途上国での活用は，共同研究での技術移転で当事国事情と調整を行い，自主自立で事業展開する体制構築を目標と
する．
Key Words：雨水吐室,
遮合流問題, 合流式下水道改善, 共同研究．
はじめに
(1) 合流式下水道システムの現状と課題 1),2)
合流式下水道で日本の改善事業は，当面の目標が汚濁負荷量削減，公衆衛生の安全，夾雑物削減であり，
長期目標はノンポイント汚濁や未処理水放流の問題解決だが，世界的にも同様の事態は発生している．
ここでは，合流式下水道システムで要の雨水吐室が,従来の改善技術は遮集分派精度が低く確実な下水道管
理は困難なため，改善事業の目標達成には高い精度の雨水吐室機能の設備や，改善事業の投資効果を定量把
握する合理的な下水道システムの開発が大きな課題である．
(2) 研究の目的と方針
本研究の目的は，確実な下水道管理で環境改善事業の投資効果を定量把握する下水道設備とシステムの開
発である. 研究の方針は，日本国が下水道改善事業で蓄積した技術や管理情報の公開データと，汎用な工学
的知見で下水道システム理論を構築し，発展途上国との共同研究で現地条件との調整や当事国が自主自立で
きる技術移転を行い，同時に本研究も更に実用的な技術改善を重ねることである．
2. 雨水吐室下水の遮集分派精度の向上
(1) 遮集分派機能の現状と問題
雨水吐室に流入する下水の遮集分派機能で標準的な仕組みを図-1 に示す 3),4) ,5) ,6)．また, 従来の雨水吐室
改善策を図-2 に示す 1)．雨水吐室設備は，計画遮集下水量見合いの流路を越流堰と遮集管渠で形成し，計画
規模を超える下水量は越流堰を超えて放流水域(河川や海等の公共水域)に分派して排除する仕組みであり，
改善策は遮集管への下水量流入調節や越流堰機能増強で直接的に対象流量を制御する仕組みだが，従来技術
は仕組みが 1 セットのため必然的に調整槽内の水位上昇を伴い，図-3 の様に遮集下水量が増大し 1)，想定以
上の豪雨時は合流式下水道システムが破綻して遮合流や未処理下水放流等の下水管理の問題が発生する．
1´
論文 ② ，2/7
■オリフィスタイプ
ポール形制御盤
（油圧ユニット内蔵）
■ヴォルテックスバルブタイプ
ヴォルテックスバルブ
オリフィス
越流堰
■落下分水タイプ
放流管渠
放流管渠
越流ぜき(堰)
流入管渠
開口
流入管渠
流入下水量(Qi)
Qi = Q1 + Q2
遮集管渠
開口
流入管渠
流入管
放流管渠
放流管渠
図-2 雨水吐室の遮集分派改善方策の概念図（平面図）
遮
集
量
( )
オリフィス分派流量 Q2
従来技術の設備
過剰遮集(Qc-Qo)
新技術の設備
Qc
(Qi)
流入量(Qi)
越流堰分派流量 Q1
図-3 合流式下水道の過大遮集下水問題の概念図
図-1 雨水吐室の概念図
(2) 本研究の流水分派理論
1) 流水分派特性の基礎理論
堰流堰の水理現象
▽
H
流水分派の基礎理論は，図-4 の越流堰と図-5 のオリフィスの水理現象を組合せ
た活用であり, 各水理現象の分派流量はそれぞれ式(1)と式(2)で算定される. な
お,ここでの水理特性(流量係数等)の一般値は日本国の公共事業で採用する技術
W
基準図書 7), 8)による.
Q1 ＝ C1・B・H3/2
(1)
3
ここで，Q1 は越流堰分派流量(m /s)，C1 は流量係数(一般値 1.8)，B は越流堰幅
(m)，H は越流水深(m)であり，図-3 の W は計画遮集下水での越流堰頂高．
Q2 ＝ C2・a・(2g・h)1/2
オリフィスの水理現象
(2)
入孔口の水没深はオリフィス孔口高の 1.3 倍以上が一般値である．なお，C2 は
▽
水没深
リフィス孔面積(m2)，h は水頭差(m)であり，オリフィス現象の発現に必要な流
a
ここで，Q2 はオリフィス分派流量(m /s)，C2 は流量係数(一般値 0.6)，a はオ
h
▽
3
空中放流より潜りタイプのオリフィスが若干小さく，完全潜りオリフィスは水
理学的に大型小型の区別は無い 9), 10)．
図-4 流水分派の流況概念図
2)
流入下水の遮集分派理論と改善方策
流入下水量の増加は雨水吐室の調整槽内の水位上昇を伴う．この際，式(1)と式(2)の関係で越流堰の流量
増加に比べオリフィスの流量増加は非常に小さいことから，流量の固定化を図る遮集下水ルートはオリフィ
スタイプ，増加流量の速やかな排除を図る放流下水ルートは越流堰タイプの水理現象を 1 セットとした活用
が下水の遮集分派理論の基本となる．
遮集分派機能の改善方策は,図-2 の様に従来技術は 1 セットの遮集分派装置で対象流量制御を行う直接制
御方式のために水理学的にも遮集分派誤差を多く含む．本研究の雨水吐室改善策(以下は新技術と記述)は雨
水吐室空間に複数セットを設けて各調整槽毎で順番に水位を制御し,効果的に最終調整槽の水位固定化を図
って対象流量を制御する間接制御方式で改善効果は非常に高い．この理論での雨水吐室の水理現象を,後述の
事業事例から図-6，図-7 に概念図を作成して以下に添付する．
2´
論文 ② ，3/7
調整槽 3 槽でオリフィス制御無し
調整槽 1 槽でオリフィス孔 2/3 に制御
(絞込み 67%)
Φ
B2 = 3.0m B1 = 3.0m オリフィス 0.350m
= 1.25
∴遮集誤差 25%
WL ▽
▽
▽
▽
⊿ h = 0.0122
0.5301
1/2
0.2365 m
(0.5301+0.2966) 1/2
0.0539 m
B3 = 7.0 m
WL ▽
0.4444 m
▽
0.5301m
WL
流入管 Φ1.5m
オリフィス Φ0.286m
B = 13.0 m
⊿ H = 0.2966 m
流入管 Φ1.5m
(0.2365+0.0122) 1/2
0.2365 1/2
= 1.025
∴遮集誤差 2.5%
図-5 従来技術（調整槽 1 槽）と新技術（調整槽 3 槽）の流水分派機能の概念図
(3)
流水分派理論の検証
1) 検証事項と判定方法
検証事項は遮集管下水量の遮集分派誤差とし,検証モデルでの数値解析の理論解で水理現象を特定して代
表モデルの水理模型実験で確認し,下水道の管理実務の視点で評価して新技術の流水分派理論の合理性と実
用性を判定する．
検証モデルは,遮集分派設備が従来技術 1 セット,新技術は複数セットとし,表-1 に各モデル形態を示す．
表-1 主要構成寸法表
従来技術
13.0 m×1 槽
6.5 m×2 槽
4.33 m×3 槽
3.25 m×4 槽
0.350 m, Φ0.286 m, Φ0.247 m
同左
同左
同左
越流堰幅と調整槽数
オリフィス口径
Φ
新技術
検証方法は, 計画遮集量(Q0)と流入量(Qi)の比率，及び遮集量(Qc)の超過分(Qc－Q0)との相関性のデータ
を以下の計算式で無次元化に整理して水理現象特性を特定し，下水道計画の一般範囲で評価する．
下水流量比(倍) ＝流入量(Qi)／計画遮集量(Q0)
(3)
遮集誤差(%) ＝ {超過遮集量(Qc－Q0)／計画遮集量(Q0)}×100
(4)
2)
検証結果
図-7 に数値解析データ, 図-8 に水理模型実験データを整理し,下水流量比は事業計画範囲の中間値 50%に
着目して評価する．
概ね 1/109～1/145
調整槽の
複数化効果
（倍）
概ね 1/41～1/52
概ね 1/10～ 1/12
4-M
200
3-S
4-L
3-M
100
20
1槽
2-L
2-M
1-S
表-2 遮集下水の分派誤差の改善効果表
1-L
1-M
1/1.4
50
2槽
2-S
3-L
1/41
4-S
3槽
1/1.2
1/10
4槽
一般範囲
下水流量比（流入下水流量(Qi)／計画遮集下水量(Q0)）
1,000
10
オリフィス孔
絞り効果
≒1/1.6
≒1/1.5
≒1/1.4
≒1/1.2
1/1.6
5
1
0.01
0.1
1
10
100
1,000 (%)
遮集下水量の遮集誤差（過大遮集下水量(Q2-Q0)／計画遮集下水量(Q0)×100）
図-6 新技術による遮集誤差の改善効果（数値解析結果）
3´
1/109
1/1.5
２０
下水流量比（流入下水流量(Qi)／計画遮集下水量(Qo)）
論文 ② ，4/7
遮集下水量の分派誤差（過大遮集下水量 ( Qc - Q o)／計画遮集下水量 ( Q o)）
図-7 水理模型実験の水理特性判定図
3)
評価及び判定
雨水吐室機能の理論解は, 図-8 から調整槽 1 槽でオリフィス孔面積 1/2 の絞り込みは分派誤差を 1/1.2 に
改善する．調整槽複数化は調整送 1 槽の分派誤差を調整槽 2 槽で 1/10，3 槽で 1/41，4 槽で 1/109 に改善する．
水理現象の特性は,調整槽数の多さや流入下水量(Qi)の大きい方が高い遮集分派精度を発現し, 図-8 の関
係曲線は直立化する．図-9 の水理模型実験は,調整槽 1 槽で概ね理論解との関係曲線は一致するが調整槽 3
槽は実験計測の限界から分派誤差 3%付近で直立化し,調整槽 1 槽の概ね 1/15 の改善効果を提示している．
この結果,遮集分派精度の改善対策は従来技術の直接制御方式に比べて新技術の間接制御方式は非常に高
い効果を発揮し,合流式下水道で確実な下水の雨水吐室管理は可能で過剰遮集等の現状課題は概ね解決する．
3
合流式下水道システムの最適化
(1)
1)
発展途上国での下水道システムの有様と概要
下水道システム採択での現状課題と着目点
下水道システムには,廉価で迅速に一定の環境改善を図るが確実な下水管理が困難な合流式下水道と,高価
格で整備期間は長いが汚水管理の確実な分流式がある．発展途上国の下水道整備は,限られた投資で緊急整備
が必要な矛盾する問題解決が重要課題であり,その解決に対象技術の発展性や自主自立の事業経営が可能か
否か,及び共同開発への着目が最も重要である．
2)
新技術活用の下水道システム
新技術活用の下水道システムは,確実な雨水吐室機能と所定規模の滞水池で遮集下水流量の滞留による制
御方法で下水管理を行い，流域地形や下水道施設管理,及び事業投資で的確な下水量配分と関係施設配置を計
画し，最も効率的に環境事業の投資効果を発揮する合流式下水道での改善システムの特定であり，下水道事
業の大幅なコスト縮減や簡素な施設管理で適切な事業経営の合理化を図れる．
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(2) 事業事例の概略設計の結果
事業事例を参考モデルに概略設計を行い，新技術活用の下水道システムの改善効果を以下に整理する。
1) 計画条件
本検証の概略設計での計画条件を表-3 に整理する．
表-3 検証事例の計画諸元一覧表
A＝30.34ha,
流出係数
f＝0.7
流域諸元
対象流域
排水計画諸元
計画汚水量(晴天時最大汚水量)
＊1
計画遮集下水量(6Qa 以上 )
Qa＝0.0200 m3/s
Q0＝0.1243 m3/s
＊1
：従来は 3Qa 以上だが、b)項対応から 6Qa 以上とする。
改善計画諸元
計画下水量(Qa＋計画雨水量)
Qr＝0.0200 m3/s＋3.9153 m3/s＝3.9353 m3/s
環境汚濁負荷の削減(貯留規模)
rv＝5mm＊2
＊2
：(2), 3), a)項の初期雨水の貯留規模 3mm～5mm 程度で当初計画に整合。
公衆衛生の安全(遮集雨水量)
ro＝(0.1243－0.020)m3/s×360／(30.34ha×0.7)＝1.768 mm/hr＊3
＊3
下流管渠事故防止(遮集量上限)
：(2), 3), b)項の遮集雨水量 1 mm/hr～2 mm/hr 範囲で当初計画に整合。
maxrc＝0.1243 m3/s×1.6＝0.1989 m3/s
2) 改善効果と施設配置の概略設計結果
本検証の数値解析結果と施設概略設計結果を関係付けて，概要を図-10 と表-4 に整理する．
※：国内論文の図を転用
図-8 対象降雨別の対策効果・対策規模相関図※
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表-4 改善対策プランの計画方針一覧
プラン区分
従来技術
新技術
改善対策の計画方針
施設概要
当面課題と管路事故対策
雨水吐室調整槽 1 槽（B24 m×Φ0.35 m）
A 案同上
雨水吐室調整槽 3 槽（B3 m･3 m･7 m×Φ0.35 m），分流室調整槽 3 槽（B3 m･3 m･5 m×φ0.35 m）
B 案同上+未処理下水放流回避
雨水吐室調整槽 3 槽（同上）
，
分流室調整槽 3 槽(B3 m･3 m･5 m×Φ0.25 m)
C 案同上+簡易処理水放流回避
雨水吐室調整槽 3 槽（同上）
，
分流室調整槽 3 槽（ B 3 m･3 m･5 m× Φ 0.15 m）
表-5 下水道システムの概略設計結果一覧表
従来技術
新技術 A 案
新技術 B 案
新技術 C 案
汚濁負荷量削減 (a)項)
○
○
○
○
公衆衛生の安全 (b)項)
○
○
○
○
計画案
改善効果
遮集下水の分派精度
処理場機能
△(誤差 59%)
◎(誤差 1%以下)
3
0.0200 m /s
0.0200 m /s
0.0192 m3/s
簡易処理下水
0.0400 m3/s
0.0400 m3/s
0.0385 m3/s
－(設備不要)
3
0.0787 m /s
0.0642 m /s
－(設備不要)
－(設備不要)
3
3
3
1,071 m3(152%)
706 m
滞水池容量
雨水吐室
＋
滞水池
3
3
◎(誤差 1%以下)
0.0200 m /s
土木施設
3
◎(誤差 1%以下)
高級処理下水
未処理下水
事業費
△：やや満足、○：満足、◎：十分に満足
749 m
(100%)
12 百万円/年(100%)
(106%)
13 百万円/年(108%)
946 m
(134%)
16 百万円/年(133%)
18 百万円/年(150%)
3) 下水道システムの流量配分と施設配置の計画全様
下水道システムの全体像を把握のため，従来技術と新技術 C 案の下水量配分と関連施設配置を整理する．
図-9 従来技術の合流式下水道システムの解析結果
図-10 新技術の合流式下水道最適化システムの解析結果
6´
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(3) 下水道の最適化システムの検証結果
改善効果は，表-4 より従来技術は遮集分派誤差が 59%と大きく確実な下水道管理は困難であり，遮合流や
未処理水放流等の課題は解決できない．一方,新技術は遮集分派誤差が 1%以下で確実な下水管理を実施でき，
合流式下水道改善事業の当面の課題に加えて将来の環境課題も解決する．
事業効果は，図-11 の従来技術システムは高級処理水下水量に加えて簡易処理下水量や未処理下水量も処理
場施設に分派され, 公共水域の環境低下を招く要因となる．一方，図-12 の新技術活用で最適化したシステ
ムは滞水池容量 52％の拡張対策で処理場施設への分派は高級処理水下水量だけとなり,公共水域には完全処
理水だけの放流も可能で公共水域の環境改善効果を大きく高める．
事業投資は,本研究に今後の下水量計画や施設配置計画で改善の余地があるものの，処理場での煩雑で高度
な維持管理を伴う高価な機械・電気系統の設備投資を，自主管理が可能で簡便な維持管理と廉価な土木施設
系統への設備投資で補うことで巨額のコスト縮減ができる．このため，発展途上国に限らず先進国もこの最
適化システムの活用は，透明性や費用対効果の高い環境事業が可能なことを示唆している．
4. まとめ
本研究は，基礎技術で確実な下水管理ができる遮集分派設備を開発し，応用技術で環境事業の投資と改善
効果の相関性を定量化して，効果的な事業経営のできる合流式下水道最適化のシステム事例を提示した．
発展途上国の下水道整備は限られた投資と緊急性を要するが，本研究の下水道システムはこの要請に適合
する．なお，当事国の下水道管理の基礎データ不足の問題は，計画条件を日本国や近隣国の類似流域での基
礎データ活用で下水道整備を進め，施設供用後で経年的に集積した基礎調査データに基づき当該事業の保全
や追加工事で対応する段階的な事業投資が，当事国事情に最適な事業運営と考えている．
本研究は，事業実施で多くの改善点の発生も予測されるが，これ等は当事国との共同研究を通しての多様
な事業計画の条件として更なる改善策を検討し，実務を通して本理論の完成度を更に高めたい．
参考文献及び公報資料
1)
(社法)日本下水道協会：合流式下水道改善対策指針と解説，pp.8-10，pp.65-67，pp.122-123，pp.153-159，
p.163，2002/6．
2) 国土交通省都市地域整備局下水道部：合流式下水道改善対策に関する調査報告書，pp.I-23-I-30，
pp.Ⅱ-65-Ⅱ-67，pp.Ⅱ-130-Ⅱ-147，pp.Ⅱ-200-Ⅱ-204，2002/3．
3) (社法)日本下水道協会：水道施設計画・設計指針の解説，pp.106-119，pp.259-262，2010/1．
4)
(財法)下水道新技術推進機構：合流式下水道改善対策ろ過スクリーン技術マニュアル，pp.7-13，2003/3．
5)
Giudice, G. D. and Hager, W. H. (1999) Sewer Sideweir with Throttling Pipe, Journal of Irrigation and Drainage
Engineering, Vol. 125, No. 5, pp.298-306, September.
6)
7)
Hager, W. H. (1999) Wastewater Hydraulics, Theory and Practice, pp.513-566, Springer.
(社法)日本河川協会：防災調節地等技術基準(案)，pp.85-92，2002/10．
8) (社法)日本下水道協会：下水道雨水調整池技術基準(案)，pp.18-19，2007/3．
9) 椿東一郎，荒木正夫共著：水理学演習(上巻)，pp.197-208，森北出版㈱，1978/3．
10) 本間仁，安芸耕一共著：物部水理学，pp.190-199，㈱岩波書店，1962/7．
11) 東京都下水道局：[PDF]東京都の合流式下水道改善．
12) 東京都河川局：東京都内の中小河川における今後の整備の有り方，pp.6-7，2012/11．
13) (財法)国土開発技術研究センター：都市河川計画の手引き･洪水防御計画編，pp.43-116，1993/6．
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2.625m
-1
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1
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3
0.0269m 0.0197m 0.0150 m
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0.333m
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0.0995
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0.250m
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0.150m
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N- 2- 2- 4( 3/ 3)
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Qi
Q1
Q2(m3/s)
(3)
Q2
(
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( %)
)
( 4)
( 5)
(Qi)
( %)
( Q2)
{
(Q0)
(4)
(Q0)} × 100
(Q2- Q0)
(5)
1
-2
Qi/ Q0
1
20 100
30
1
0.0269m
0.0197m
20%
29%
0.0150m
12%
0.0150m
0.0269m
31%
59% =(29-12)/29×100
Type D
29%
3
1
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-2
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×
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0.060m 2
-3 3
3
-3
3
3
0.0045m 1
0.0012m
1
1/13
3
2 3
1
,
690- 8518
TEL 0852-36-5225 E-mail [email protected]
( 373)
B1
, Vol . 70, pp. 45- 59, 2014.
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1 ,2 ,3
4
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2002
, pp.59-67, pp.71-84, p.122, 2002.6.
2
pp.2-8-2-29, 2008.3.
3
pp.II-121- II-159, 2002.3.
4
B1
No.2, pp.49-59, 2014.
Vol.70
5 Syuhei ODA Kohei ODA Shinji ARAO Study on Optimisation of Combined Sewer System with New
Diversion Chamber 13thInternational Conference on Urban Drainage, Sarawak, Malaysia, 7-12 September 2014, Abstract ID-2514713
1-34-11 TEL 03-5363-6770
( 376)
E-mail [email protected]
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,
60
,2016
RESEARCH ON RAINWATER DISCHARGE CHAMBER WHICH CAN
CONTROL FLOW RATE OF INTERCEPTED SEWAGE DURING HEAVY RAIN
Shinji ARAO, Takahiro NAGAOKA, Mai KADA, Ran TAGAMI, Kosuke NAKAMURA,
Shuhei ODA and Kohei ODA
1
( 690-8518
2
( 163-1031
3
14-4)
3-7-1
( 940-2137
4
31
1603-1)
( 690-8518
5
)
( 160-0022
14-4)
1-34-11)
In the rainwater discharge chamber of the combined sewer system, it is difficult to control the flow rate of the
intercepted sewage to the sewage treatment plant at the time of heavy rain, and a part of the sewage from the sewage
treatment plant is discharged untreated into the sea. To overcome this problem, it is necessary to develop the facility
which can control the flow rate in the interceptor sewer. Recently, by authors, a new technology of sewer system has
been proposed in which the rainwater discharge chamber has multiple regulation tanks and which has the high
performance of controlling the water level in the regulation tanks and flow rate of intercepted sewage into the
treatment plant. In the new rainwater discharge chamber with two regulation tanks, the interception error (excessive
flow rate of intercepted sewage/planned flow rate of intercepted sewage) becomes 3% to 8%.
Key Words : Combined sewer system, intercepted sewage, orifice, rainwater discharge chamber, side weir
15
35
I_583
2
論文 ⑦ ，2/6
3
1/13
0.500m
3
2.625m
1
1.000m
0.150m
2
0.0505m
2
3
1
=0.0269m 0.0197m 0.0150m
2
2
3
1
1
(1)
Qi(m3/s)
Q1(m3/s)
Q2(m3/s)
(1)
Q1 m3/s
(2)
(2)
C1
H
m
1.8
m
Q2 m3/s
L
(3)
(3)
m2
0.6
C2
h
a
Qi
m
Q1
3/2
Q2
1/2
Q1
Q2
0.0995m
Q1
I_584
0.15m
Q2
論文 ⑦ ，3/6
3
1.000m
0.333m
1
3
0.0995m
2
0.667m
0.333m
0.00001 m 0.01 mm
3
2
1
3
3
3
2
3
3
1
2
1
0.150m
3
3
200kg
2
2
2
0.250m
1.000m
1
0.200m
1m
1
0.150m
1
2
3
2
0.0m 0.167m
0.333m
0.50m 0.667m
3
Type D Type G
10
I_585
2
論文 ⑦ ，4/6
1
3
(4)
(5)
Qi(m3/s)
Q2(m3/s)
3
Q (m3/s)
2
(1)
Qi(m3/s)
Q1(m3/s)
Q2(m3/s)
20
100
3
1
1
2
3
(4)
30
Q2
%
Type D
Q
(5)
3
1.00m
0.0268m 0.0269
3
3
1
Q2
1%
80
3
Qi
, 1
2%
I_586
Type D
29%
Type A
Type F
Type C
0.0150m
25%
3
論文 ⑦ ，5/6
2
3
3
2
1
3
0.00934m3/s
3
0.0045m 1
1
0.060m 2
0.0012m
2
3
2
2
1
0.0269m
Type G
6
30
3
Type G
7.6
7.8
14
10
10-2
7
Qi Qo
3
Type F
Type D
6
2
5
Type I
4
1
3
2
0.00955m3/s
0.040m 1
2
2
0.0036m
1
0
0
3
1
2
2
0.667m
3
2
I_587
1
2
3
4
5
6
3/s)
7
8
9
10
10-3
論文 ⑦ ，6/6
pp.7-13 2003
2
4.5
4.0
3.5
Vol.37
3.0
No.448
pp.151-164 2000
2.5
3
2.0
1.5
48
1.0
pp.529-534 2004
0.5
4
0.0
0
1
2
3
4
5
6
7
8
9
10
Vol.10 pp.675-682 2007
5
B1
0.009545m3/s
0.004990m3/s
0.002040m3/s
0.007914m3/s
0.003668m3/s
0.001522m3/s
0.00638m3/s
0.002519m3/s
0.000894m3/s
Vol.67 pp.901-906 2011
6
70
4.5
2
4.0
7) Hager, W. H.
3.5
pp.101-102 2015
Lateral outflow over side weirs, J. Hydraulic
Engineering, Vol.113, No.4, pp.491-504, 1987 : Discussion
3.0
Vol.115, No.5, pp.684-688, 1989.
2.5
2.0
8) Subramanya, K., and Awasthy, S. C. : Spatially varied flow over
1.5
side weirs, Journal of the Hydraulics Division, ASCE, Vol.98, No.1,
1.0
pp.1-10, 1972.
0.5
9)
0.0
0.00
0.17
0.33
0.50
2
0.67
pp.19-27
1996.
10)
2
pp.31-38
1996.
CSO
11)
Vol.7, No.27, pp.18-25, 1999.
2
2
0.333m
0.667m
3
0.5
8
3
2
12
4
2001.
:
13)
B1
1
Vol.70 No.2 pp.49-59 2014
14) Shuhei Oda, Kohei Oda, Shinji Arao : Study on optimization of
combined sewer system with new diversion chamber 13th ICUD
Kuching Sarawak Malaysia 2014
:
15)
,
52
pp.371-373 2015.
:
16)
Vol.52 No.634
pp.136-142 2015
1)
:
I_588
論文 ⑧ ，1/3
1),2),3)
5),6)
5),6)
1
5),6)
1),2),3),4)
5),6)
論文 ⑧ ，2/3
1
3
1
1/2.08
3
1/12.7
1
1
1/1.78
2
3
1/4.2
1/8.9
1
2
1/3.4
1/1.45
論文 ⑧ ，3/3
2 15%
10 50%
5)
1
2009
2
2002
pp.35-57,106-119,259-262,2010.1.
pp.38-59,118-134,153-169,269-281,392,2002.6.
3
pp.2-8-2-29,2008.3.
4
pp.10-18,69-86,2001.3.
5
B1
No.2, pp.49-59,2014.
Vol.70,
6
Vol.52,No634, pp.136-142,2015.8.
1-34-11
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