Engineering cost management of Guangong 'ao Hydropower Station
Author: Xiao Tianyi Upload: Ye Guiren Source: Water Conservancy Engineering Network 2005-09- 12 00:00
Guangong 'ao Hydropower Station is located on the main stream of Luokouxi in Qingliu County, Fujian Province. Luokouxi, a tributary of Jiulong River, belongs to Shaxi River system in Minjiang River Basin. The dam site of this project is located on the Luokouxi River, about 700 meters upstream of the intersection of Changtan River and Luokouxi River. The control basin area above the dam site is 1220km2, and the total storage capacity of the reservoir is 7.3 million m3. This project is mainly for power generation, with a total installed capacity of 2×8000kw. It is the largest hydropower station in Qingliu County. The power station hub consists of a barrage, a power generation and diversion system, a powerhouse behind the dam and a booster substation. The barrage is a fine aggregate concrete masonry gravity dam with a maximum dam height of 39m. The dam crest overflows and discharges flood, and the wide tail pier and bucket are combined to dissipate energy. This power station project is jointly built by Xiamen Youen Electric Power Co., Ltd. of Sanming Electric Power Bureau of Fujian Province and Qingliu County People's Government of Fujian Province (the investment ratio is 70%: 30%), and the estimated total investment is 9,265,438+200,000 yuan. It was officially started in July 2000 and completed and put into operation in June 2003. A series of systems such as owner responsibility system, bidding system, construction supervision system and contract management system have been established in the implementation of engineering projects, and the project has been effectively managed.
1 Implement the owner responsibility system and improve the initiative of cost control.
As the direct manager and beneficiary of the project, the project owner should be responsible for the whole process of project planning, financing, construction, operation, loan repayment and asset preservation, always aiming at improving the overall economic benefit of the power station and controlling the project quality, project cost and construction period, which determines the role and position of the owner. Guan Gong 'ao Hydropower Station set up a capable project legal person in the early stage of the project construction, and established the owner unit-Fujian Liu Qing Guan Gong 'ao Electric Power Co., Ltd. (hereinafter referred to as Guan Gong 'ao Electric Power Co., Ltd.) according to the modern enterprise system, so as to earnestly fulfill the owner's responsibilities, enable the enterprise to have enough autonomy, reasonably allocate funds according to the actual project progress and investment completion, make timely decisions, deal with various problems encountered in the project construction process, and dare to adopt new technologies and processes to ensure the project construction.
2. Optimize the design scheme and reduce the project cost.
Design is the foundation of capital construction, and the design scheme of hydropower station is the most basic element of project investment and the primary link to control project cost. Due to the complex engineering geological structure of Guangong 'ao Hydropower Station, limited by the depth of previous geological exploration, supplementary geological exploration and demonstration are required for the original dam energy dissipation scheme when the preliminary design is reviewed and approved. Through the hydraulic model test results and design scheme demonstration, the energy dissipation scheme is changed to the energy dissipation design with wide tail pier and bucket, which increases the investment of wide tail pier and bucket, and the geological conditions revealed by actual excavation are much worse than expected, which is a rare geological structure and foundation in Fujian Province. In view of the engineering practice, Guangongwa Electric Power Company pays close attention to the optimization of design scheme, boldly brings forth new ideas, and gives full play to the intelligence of engineering and technical personnel. It has invited well-known experts and scholars from Hohai University, Central South College, Fujian Provincial Water Resources Department, Fujian Provincial Water Conservancy Society Committee and other parties to give guidance, offer suggestions, solve engineering and technical problems and optimize the design scheme. By optimizing the design scheme, the project cost is saved and the total investment of the whole project is effectively controlled within the budgetary estimate.
(1) Optimization of construction diversion scheme. In the first stage of the original design, the left bank open channel was used for diversion. During the construction, when the first-stage diversion channel platform excavation was basically completed, due to geological reasons, a large landslide (1# landslide) occurred on the left bank slope, completely covering the diversion channel platform and the dam energy dissipation pool. The construction period has been delayed for more than three months, and the project construction has reached a deadlock. The owner shall timely organize the technical strength of the owner, design, supervision units and contractors, and invite experts from Central South Institute to discuss good strategies on the spot. After comparison and careful demonstration of several schemes, the design unit agreed to change the left bank diversion scheme to the right bank diversion scheme, and arranged the first-class diversion channel in the right bank power generation diversion system, draft tube and tailwater of the main powerhouse, and reserved the longitudinal rock ridge as the longitudinal weir for the excavation of the right bank diversion channel, which solved the diversion problem. Save the investment of diversion project by more than 654.38+800,000 yuan, shorten the excavation period of the main project and regain the construction period.
(2) Optimization of grouting block stone scheme for dam face and dam cutoff wall. At the beginning, the upstream and downstream dam faces were all monolithic masonry structures, and the concrete cutoff wall was set on the upstream side of the dam. Due to the limitation of ground materials, the trial mining in the quarry proved that the whole masonry could not be mined. In the construction design, Guangong 'ao Electric Power Co., Ltd. put forward the scheme that the upstream dam face is changed into concrete impervious face, the dam impervious wall is cancelled, and the downstream dam face adopts cast-in-place concrete dam face, which provided demonstration and design for the design unit and was successfully implemented. It solves the problem of lack of ground materials, saves more than 600,000 yuan in engineering cost, speeds up the construction progress, shortens the construction period and improves the anti-seepage effect of the dam.
(3) Optimization of layout scheme of booster station. The original design booster station is arranged at the top of the downstream side of the right bank dam (about 0-035m below the dam), with a design elevation of 3 15.00m (the design elevation of the dam top and the pavement elevation of Shangba highway are 294.00m). The layout scheme occupies a lot of forest land, and the cost of land acquisition and forest compensation is high; Large amount of earthwork excavation; The inner side is next to the dormitory building of a forest farm, and the blasting risk is high; The transportation problem of main transformer and other equipment is difficult to solve. In view of the engineering practice, combined with the accumulated experience in the construction process, we boldly explored and proposed to move the booster station from the top of the mountain to the upstream side of the right bank dam (0+065435kv8+00m above the dam) and arrange it on the original platform (where the contractor's vehicle repair shop is located), which has been backfilled with stone slag for 3 years. The designed ground elevation is 298.00, which is only higher than the dam. Here, the dam road is connected, and the excavation amount is very small, which does not occupy forest land. The booster station has compact layout, convenient equipment transportation and better scheme. After approval, the design unit is provided to optimize the design and implement it, with good results. The optimization of this scheme reduces the requisition of forest land by more than 3,200 m2 and the excavation of earthwork by more than 60,000 m3, saves the project cost by more than 2 million yuan, shortens the construction period by about 3 months, greatly reduces the project cost, and effectively controls the total investment of the whole project within the budgetary estimate.
(4) Optimization of financing scheme. In the case of insufficient construction funds, Xiamen Youen Electric Power Co., Ltd., Sanming Electric Power Bureau, was introduced to invest and hold shares through the mechanism of external introduction and internal connection. The actual total loan from the bank is only 44.8 million yuan, which is 6.5438+0.65438+0.98 million yuan less than the original forecast of 56.78 million yuan. In addition, the national loan interest rate was lowered, and the loan interest was reduced from the original 9.92 million yuan to 6120,000 yuan.
3. Select the contractor through bidding.
(1) Reasonable bidding. Reasonable bidding is the premise of bidding, and it is also a necessary condition to reduce construction interference, speed up project progress and reduce project cost. At the beginning of construction, Guangong 'ao Electric Power Co., Ltd., based on the principle of "possibility, separability and overall benefit", fully considered that it should not only be conducive to the formation of a competitive situation, but also minimize construction interference and facilitate coordination among construction units, and divided the main project of Guangong 'ao Hydropower Station into five sections, namely, bidding for civil works of barrage (including earthwork excavation of powerhouse and booster substation) and bidding for civil works of powerhouse behind dam (including booster substation) at the same time. Put the project construction and equipment procurement in an open, just and fair competitive environment, fully consider various factors such as cost performance, professional level and corporate reputation, and select good contractors such as design, consultation, construction, supervision and supply from the competition. Through the implementation of competition mechanism and taking advantage of the low price of steel in the market at that time, the total contract price of manufacturing and installation costs of hydro-generator sets and electromechanical equipment was only 8.8 million yuan, which was 9.65 million yuan less than the original estimate of18.45 million yuan. In this way, it is not only convenient to control the project cost, but also creates favorable conditions for ensuring the quality and progress of the project.
(2) Reasonable bid evaluation and calibration. Considering the complex engineering geology, high construction intensity, great difficulty, high technical content and tight construction period of Guangong 'ao Hydropower Station, the construction unit is determined by inviting or public bidding for different projects, and the qualification of the construction unit is clearly required from the aspects of dam type requirements, construction conditions and technical equipment level. The whole bidding process has always been carried out under the guidance of Fujian Provincial Bidding Office and under the supervision of Fujian Provincial Water Resources Department and other relevant departments, in line with the principle of "openness, fairness, impartiality and transparency". Bid evaluation and calibration are mainly compared from the aspects of time limit, quality, quotation, equipment capacity, construction experience, technical measures and contract reputation, and the quotation and overall benefit of the main projects that determine the power generation time limit are quantitatively analyzed. Finally, select a group of domestic excellent water conservancy and hydropower construction enterprises and equipment with relevant manufacturing experience, such as China Minjiang Engineering Bureau, China No.1 Water Conservancy and Hydropower Engineering Bureau, Fujian Water Conservancy and Hydropower Engineering Bureau, Fujian Nanping Electric Machinery Factory, Hunan Changsha Huaneng Automation Control Co., Ltd., etc.
During the construction of Guangong 'ao Hydropower Station, except for a few new projects, the unit price of the main project has hardly been adjusted, and the investment growth is also under control. During the supply and installation of all kinds of equipment, there was no claim and quotation adjustment, and all the equipment had stable performance and normal operation in the initial operation stage. Guan Gongao's practice proves that competition can promote technological progress, optimize resource allocation and promote the transformation of enterprise management mode. Choosing a reasonable quotation and putting an end to winning the bid at a low price can guarantee the construction period, quality and control the project cost.
4. Implement project supervision system and control the whole process.
Engineering supervision is an intermediate link that connects the owners, contractors and the government's macro-management, and comprehensively supervises and manages the investment and construction activities of engineering projects. The construction supervision of Guangong 'ao Hydropower Station is undertaken by China Water Conservancy and Hydropower Construction Engineering Consulting Zhongnan Company, which implements all-weather, all-round and whole-process on-site supervision, with the goal of reasonably controlling "progress, quality and investment", strictly controlling and earnestly fulfilling the supervision responsibility of "three controls and one coordination". The supervision engineer mainly controls the project investment from the aspects of project, material use and engineering quantity measurement. In practical work, first of all, do a good job in the inspection and review of completed projects, and at the same time do a good job in the application and review of major technical measures and the calculation of concealed engineering quantities; Secondly, the use of project settlement items and materials should be determined according to the contract documents, and the settlement amount should be reviewed according to the specified principles and methods of engineering quantity measurement. On this basis, the supervision engineer of Guan Gong 'ao Hydropower Station strictly examines and signs the monthly settlement report, engineering quantity calculation, drawings and schedules of all construction units, and submits them to the owner for review after being approved by the supervisor, and pays the monthly project payment according to the contract after being reviewed by the Engineering Finance Management Section; On-site design changes and major technical measures can only be implemented after the supervision engineer has obtained a technical visa. Under this supervision system, the construction of Guangong 'ao Hydropower Station has achieved the goals of high speed, good quality, low investment and high efficiency. It is completed and put into production as planned, and the investment is controlled within the budgetary estimate.
5. Strengthen contract management and strictly control investment.
(1) Adhere to the full implementation of the contract management system. From design to construction, Guan Gong 'ao Hydropower Station always regulates the behaviors of both parties by contract, clarifies the responsibilities of both parties, contacts all parties by using the contract as a lever and bridge, gives full play to the leading role of the owner, tracks the implementation of the contract in all directions and in the whole process during the construction period, and organizes, coordinates and urges all parties to control the progress, quality and investment. Because the company has formulated strict contract management methods, defined the responsibilities of various departments, and brought the whole project management into the track of contract management, it effectively controlled the progress, quality and investment of the project.
(2) the application of modern means. Guan Gong 'ao Hydropower Project has special contract managers, who use computer technology to manage the contract from registration, payment, claim to statistics in an integrated way, so as to make the contract as detailed, complete and comprehensive as possible, and make the contract text and related economic documents correspond to the budgetary estimate project, so as to realize the budget estimate, contract price and project settlement in one account, greatly reduce errors and disputes in contract management, effectively realize the tracking management of contract execution and improve work efficiency.
(3) Establish the classification of various accounts. Guangong 'ao Hydropower Station makes full use of the characteristics of modern computer, such as high speed, large capacity and easy to query and calculate, and has established various accounts, such as contract account, settlement account, claim account, main project account, statistical account, etc., so that the factors affecting project investment control are closely linked vertically and horizontally, which greatly facilitates project managers to fully understand the completion of project investment, and also makes the data exchange between professional and technical personnel simple and comprehensive, effectively avoiding the excessive workload caused by human omissions or mistakes.
6 the difference between the total contract price and the unit price, and reasonable compensation.
During the construction of Guangong 'ao Hydropower Station, many changes, additions and compensation projects inevitably occurred. According to the actual situation and the contract, Guangong 'ao Electric Power Co., Ltd. strictly distinguishes between total price projects and unit price projects, flexibly grasps the estimated values of each project without breaking through the total budget, and makes reasonable adjustments to make it more in line with the actual needs of project construction, which is also conducive to project management and promotes the project to reach the level of "high efficiency, high quality and low consumption". During the construction of Guangong 'ao Hydropower Station, more than 200 new projects and more than 30 compensation projects occurred, with a total amount of about 6.5438+million yuan, of which the compensation amount was nearly 2 million yuan. For these projects, Guan Gong 'ao Electric Power Co., Ltd. carefully checked the bidding documents, contract documents and related commitments in accordance with the procedures of "supervision and control, on-site quantity check and company audit", and strictly measured each project in the principle of "seeking truth from facts and reasonable compensation", and resolutely refused to recognize the approved ones. "No rules, no Fiona Fang", because of the strict audit procedures and principles, the project management has a basis, which has laid a good foundation for effectively controlling the project cost.
7 conclusion
The Guangong 'ao Hydropower Station project was optimized by the owner, and the reasonable quotation was selected in the bidding stage. The project owner responsibility system, project construction supervision system and contract management system were fully implemented in the construction process. The actual settlement quantities of the main project were basically the same as those provided by the design, except for the newly excavated dam foundation quality defects and the corresponding backfill quantities, and the quotations of the total price and unit price projects were hardly adjusted, so the total investment of the project was effectively controlled within the budgetary estimate. The on-grid electricity price of this power station is 0.30 yuan/kW h approved by the price department. The operation and economic benefits in the past two years show that the project quality is good and the economic benefits are remarkable.