Introduction: With the acceleration of industrialization in China, water pipe networks have received increasing attention. Municipal pipe networks transport various forms of energy, thus the operational status of urban water pipelines directly impacts the quality of life. With increasing urban populations and energy consumption, pipe networks provide crucial energy supply, playing a vital role in national economic development. Therefore, construction companies should develop comprehensive management plans and innovate work methods to improve the design and construction of municipal water pipe networks, meeting relevant work demands.

Introduction

Municipal water supply networks are indispensable for urban water supply. Ensuring the construction quality of water networks is crucial for providing a stable water supply and improving the well-being of urban residents.

Pipe network planning should consider both practicality and economic efficiency, finding a balance between the two to achieve optimal design.

Material and equipment selection should prioritize quality, with additional economic investment if necessary to ensure quality.

During pipeline laying, the selection of pipe materials and quantities must be based on the actual project situation, minimizing waste.

Planning should consider the entire municipal pipe network construction, aligning with the concept of sustainable urban development.

I. Common Problems in the Current Operation and Management of Municipal Engineering Water Supply Networks

1. Significant Aging of Water Supply Networks

Currently, most domestic municipal water supply systems were built at the end of the 20th century. Many networks have been in operation for over 30 years. Limited technology at the time resulted in generally poor construction materials and quality. With use, aging has become increasingly apparent, especially in older communities.

2. Inadequate Valve Operation and Maintenance

In the operation and management of municipal water supply networks, difficulties in opening and closing valves are common, with some valves becoming unusable. This makes it difficult to quickly shut off valves during pipe bursts, leading to prolonged and widespread water outages, affecting production and daily life. Many issues remain in valve operation and management, requiring attention from water network operators.

In recent years, with the acceleration of urbanization, many municipal roads have undergone expansion construction. However, due to inadequate valve management, problems such as misplacement or improper burial of valves have occurred, increasing difficulties in operation, inspection, and maintenance, and potentially creating safety hazards.

3. Significant Water Leakage in Water Supply Networks

Currently, water loss is mainly due to: (1) crustal movement causing displacement of water supply networks, leading to detachment of pipe joint seals or pipe breakage; (2) large-scale municipal engineering projects impacting water supply networks. Soil pressure imbalance during construction can break pipes. With increasing urbanization, this problem is becoming more prominent.

II. Technical Transformation Measures for Urban Water Supply Networks

1. Updating Pipe Materials

Currently, China uses both metallic and non-metallic pipes for water supply. Different materials have different properties, applicability, and leakage rates.

Data shows that many tier-three cities and rural areas use cement and cast iron pipes. Cast iron pipes have the highest leakage rate, with an average of 4.5 leaks per 10km. Cement, steel, and cast iron pipes have the highest leakage rates. Data from developed countries shows that steel, cast iron, and cement pipes are the main causes of water loss. For example, data from several German cities showed that steel pipes had the highest leakage frequency (0.26 per km*year), followed by cast iron pipes (0.23 per km*year). This is a global issue, leading many countries to adopt GRP pipes, although their high cost remains a drawback.

In recent years, China has significantly reduced or banned the use of steel and cast iron pipes, yielding positive results. We should continue to focus on new materials, such as environmentally friendly plastics, accelerating testing and network upgrades.

2. Adopting Zonal Control, Regular Inspection, and Maintenance

Zonal management combines metering zones, pressure zones, and management zones.

Metering zones (DMA) are categorized into small, medium, and large, corresponding to household numbers of <1000, 1000-3000, and 3000-5000, respectively. Zonal metering allows for the timely identification and location of pipe bursts and leaks, enabling prompt repairs.

Pressure zoning facilitates year-end data aggregation (total water usage, output, and loss). However, detailed water condition information for individual zones is difficult to collect. Each area has its own pressure. Understanding urban topography and implementing differentiated pressure supply can effectively alleviate overall network pressure.

Management zoning ideally utilizes natural geographical features or boundaries like railways and roads for area division. Continuous monitoring is essential. Traditional methods, such as ground listening to detect leaks, are still used, but are inefficient and susceptible to noise interference, often requiring nighttime inspections.

With the development of new intelligent technologies, the old acoustic detection method is gradually being abandoned. Automated pipe networks utilize the conductivity of metal within pipes to emit electromagnetic waves or flowing water molecules for real-time monitoring. New inventions, such as deploying miniature robots in water flow, exist, but currently, the high cost hinders widespread adoption. However, with technological advancements, intelligent monitoring and control technologies for pipe network leakage will become increasingly mature.

The long-term benefits of intelligent detection of pipe network leakage are considerable, significantly reducing leakage. Leakage prediction utilizes intelligent pipe network data prediction, incorporating various algorithms and formulas such as genetic algorithms, ant colony algorithms, Bayesian formulas, and neural network theory. These continuously analyze data and provide probability prediction reports of leakage occurrences, enabling timely maintenance and repair before major leaks happen. Smarter management reduces human error and reveals patterns through big data analysis.

3. Pipe Installation

Following the above procedures, the water supply pipe installation phase officially begins. Before construction, the trench foundation treatment and pipe material quality must be inspected; installation can only proceed after meeting standards. Pre-fabricated pipe sections are lowered into the trench in sequence, strictly controlling the pipe's position to prevent scraping against the trench walls. Protective measures are taken during pipe transportation within the trench to avoid disturbing the original ground. Installation begins from the downstream and progresses in the construction direction.

During pipe installation, timely inspections are conducted. Based on the results, the center and elevation of the pipe sections are adjusted. Only after ensuring the correct installation of a section can the next section be installed, repeating this process until all pipes are in place. Since debris can easily enter during pipe installation, it must be promptly cleaned. All pipes must be tightly connected to form a complete pipe network system. Slopes exceeding 15% increase construction difficulty; protective measures must be taken during machinery operation to prevent tipping. During flexible joint pipe installation, anti-slip measures are required for sections with slopes exceeding 18%; for rigid pipes, anti-slip measures are still needed when slopes exceed 35%.

Additionally, during pipe installation, each pipe valve must be individually inspected, and any problems must be promptly identified and addressed.

4. HDPE Pipes

Measurements are taken according to design requirements, and excavation width lines are marked on the road surface. After completing the cutting operation, the pipe earthwork excavation phase begins. To improve efficiency, mechanical excavation is primarily used, with workers assisting in finishing and cleaning. Pipe excavation should be linear, with the trench bottom width at least DN+0.30m. In sections with underground connections, the trench bottom width can be appropriately increased to at least DN+0.50m to facilitate smooth installation and connection.

As the trench excavation progresses, once the design bottom elevation is reached, excavation stops, and manual trench cleaning is performed to ensure cleanliness before checking the soil quality. The slope stakes are re-measured; if correct, a line is strung. The line is thoroughly checked to ensure alignment with the trench bottom; any discrepancies require adjustment. The pipe bottom should be stable, so compaction measures are recommended, with inspections after each compaction operation.

After the concealed inspection of the trench is completed and the measured results meet the requirements, pipe installation can begin. In areas with insufficient space around the trench, connection and installation are done within the trench; if sufficient space is available, the pipes are connected and then installed as a whole. Before installation, the quality of all pipe materials must be thoroughly checked for dents, cracks, etc. During construction at critical points such as pipe bends and tees, it is advisable to set up supports (made with C20 concrete as the base material). Supports at flange valves are brick-built for reinforcement. When HDPE main or branch pipes connect to other components (valves, metal pipes, etc.), using plastic-steel transition joints is feasible to ensure a tight connection. Air release valves should be installed in raised and uphill sections to reduce the impact of air and water on the pipes, maintaining their integrity and stability. Given the good flexibility and elasticity of HDPE pipes, expansion joints are not necessary during installation.

5. Key Points of Leak Detection

Leak detection in water supply networks is crucial for analyzing pipe tightness, but involves many factors. Before detection, a feasible plan must be developed based on the actual situation. To improve accuracy, professional equipment is needed, along with training for personnel to enhance their skills and professional ethics, coordinating human and machine resources for efficient leak detection.

Specialized personnel should conduct regular inspections, promptly identifying and addressing anomalies to prevent damage. When leaks are found, the causes must be analyzed, and effective measures taken to eliminate the root causes and prevent adverse effects on subsequent work.

6. Grid Management Model

Grid management is used in many areas, such as community management, power supply, gas supply, and municipal services, demonstrating effective resource utilization. Learning from successful grid management experiences in other fields, water supply companies have implemented a grid management model, assigning a comprehensive grid manager to each grid unit. The grid manager's responsibilities include: ① Daily inspection of water supply facilities, mainly pipes, valve wells, and pump rooms, checking for normal operation and contacting relevant departments for repairs and follow-up if anomalies are found; ② Real-time monitoring and analysis of flow meter data on the smart water supply platform, coordinating and tracking abnormal water volumes; ③ Maintaining important user files, conducting regular user visits and follow-ups, collecting and handling user feedback on water usage issues and needs, and providing water usage consultation; ④ Handling water application requests within the grid unit, coordinating the application survey, contract signing, and acceptance stages.

Since implementing grid management, water supply services have shifted from reactive problem-solving to proactive identification and resolution. Significant improvements have been seen in engineering, pipe networks, marketing, and customer service, increasing user satisfaction and improving grid manager skills. For water supply companies, this effectively reduces pipe network leakage rates, saving operational costs.

7. Importance of Construction Acceptance

Water supply projects are fundamental and crucial in urban development, involving large-scale engineering and numerous aspects. To ensure the quality of urban water supply systems, the completion acceptance of water supply system projects must be strengthened.

The actual acceptance work should be carried out in strict accordance with the national indicators for various buildings, and the acceptance requirements for building construction should be checked in detail. Once it is found that the completed project does not meet the national standards during the inspection, the relevant responsible departments should be contacted immediately, and professional construction personnel should be arranged for rework to avoid bigger problems during construction as much as possible.

The completion acceptance work requires the pipeline construction department to strictly control the work of each link, carefully check the construction quality of each link, and once a quality problem is found in a certain link, it is necessary to re-verify the quality of the surrounding projects, and take rework or repair measures in time according to the severity of the quality problem to ensure that the construction quality of each link strictly meets the construction standards, so as to comprehensively guarantee the construction quality of the entire project.

Conclusion

In summary, the operation and management of municipal engineering water supply networks is an important work that cannot be ignored in the urban daily comprehensive management system. The effectiveness of management will directly affect whether the water supply network can be used normally, and thus determine the quality of life of the people. With the continuous improvement of social and economic construction and people's living standards, the demand for tap water resources is also increasing. Under this circumstance, relevant departments have increased the number and scale of construction of municipal water supply networks in order to supply people with high-quality and sufficient water resources.