| 英文摘要 |
The purpose of this project aims to reinforce main branch and roadside gutters of Kaohsiung
City cleaning and maintenance. For facilitate proper drainage, cleaning work is supposed to be
finished before tide season in order to avoid overfilling around city center during rainy season.
The main schemes of this project are divided into 5 programs, preliminary, inspecting gutters,
ditch cleaning, ditch dredging, checking the quality of operation and efficiency assessment.
1. Personnel and equipment configuration
In this project, the main work is based on manpower and the auxiliary are equipments. For one
team, 10 people with an engine pressure washer and sludge removal vehicles are required. The
other one is 5 people with a sewer cleaner (vacuum/jetting tanker), excavator and sludge removal
vehicles. All equipments meet regulatory requirements of this project. Moreover, an additional
excavator is using for a specific working area in order to meet demand of cleaning side sewer of
mountain.
2. Cleaning up gutters
The Contract of this project was started from 19 Sep 2012 to 18 Sep 2013. Besides gutters
cleaning program had not been accomplished in September 2013. By 15 Aug 2013, all the work
has met contract requirement. The total length of cleaned gutters is 150,114 m, which took
100.08% of the achievement rate.
Mud cleaned out from roadside gutters is transported by sludge removal vehicles (612-BU、
Z6-226) , belongs to a legal cleaning and removal industry, to landfill ( Gangshan, Qishan and
Daliao) for disposing. Total amount of cleaned volume is 1031.49 tons which is carried by146
cars.
3. Checking the quality of operation
From September 2012 to August 2013, 147 abnormal side gutters was found, including 45
serious clog caused by covering flowerpot and malignantly blocked up, and 29 illegal pipelines
hanged inside side gutters. Overall, poor construction and drain cover take 37.4% and 36.7% of
influences during cleaning side gutters, therefore quality of construction and gutters maintenance
should meet higher requirement.
In total, 130 in site checked by inspection team, including 119 are qualified and 11 with defect,
and the most of common defects could have immediate improvement, for example: workers did
not wear safety vest, lacking of traffic safety cones, no traffic directors, roadside stacked with
ditch mud without sweeping and labors worked slothfully. However, these defects had been
reformed after inspecting intensively. During the working period, occupational injuries and
accidents had never been caused.
4. Efficiency assessment
(1) Factors affecting ditch cleaning
In order to investigate factors related to design of drawdown slope, defected construction,
section and depth of gutter, intake design and construction, and pollution from surrounding.
According to inspection, 147 defective gutters could be refereed to several reasons shown as
the following, 15 defected designs, 55 defected construction, 54 defected drain cover and 23
tainted by environment. To conclude, drain construction and covers have significant
influence on ditch dredging and maintaining, which take 37.4% and 36.7 of influences
during cleaning side gutters.
(2) Gutter cleaning efficiency analysis
Regarding to result of inspection, the most relevant program of gutters cleaning is highly
recommended as the following: 15 people are arranged into a team to carry out gutters
cleaning and it also requires 1 sewer cleaner (vacuum/jetting tanker), 1 mud sweeper and
equipment. Moreover, staff arrangement is listed as the following, 1 site supervisor is in
charge, 1 traffic director, 1 gutter cleaning trunk driver, 1 sewer cleaner (vacuum) operator,
1 sewer cleaner (jetting) operator. On the other hand, 10 people are assigned to work by
manpower.
(3) Frequency of gutters cleaning
The target of this project aimed at major and minor flood-prone area in Kaohsiung
County. Based on different gutter width and surrounding, 10 roadside gutters were selected
from each area for investigating their sewer sediment. The investigative data was applied to
estimate for 12 months by logarithmic regression analysis of Microsoft Office Excel. Thus,
the recommended frequency of gutters cleaning and control objectives are referring to the
following conditions:
A. If the depth of gutter sewer = 0.15m,
(A) When gutters locate at urban residences or countryside, and the width of
roadside gutters is 4m, the control objectives should be qualified after
carrying out 16 months cleaning program. Furthermore, cleaning
frequency depends on sewer sediment after 12 months cleaning program,
therefore, cleaning squad can make the most appropriate scheme for
excusing gutters cleaning program.
(B) When gutters locate at city center and around traditional market, nearly 6
months cleaning program, the control objectives should be qualified.
However, 16 months later, it will become a potential flood-prone area.
Regarding to the consequence, 6 months cleaning scheme is the most
relevant frequency for this program. But, if there is any particular pollution
caused by emissions from factories and agriculture, frequency of cleaning
can change to 4 and 9 months. Despite the relevant frequency, the
authorities have to make more effort on inspection in order to prevent
factories discharging sludge and wastewater or agriculture and livestock
discharging pollution.
B. If seawater intrusion causes to roadside gutters clogged by sand around
low-lying coastal areas such as Ziguan, Mituo, Yong'an, Jiading, Gushan and
Yancheng Dis., the control objectives will be qualified by carrying 1 month
gutters cleaning program. 2 months later, these will become potential
flood-prone areas, so carrying on gutters cleaning program per month is
necessary.
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