Traffic construction has always been the highlight of infrastructure construction, and speeding up highway construction is an important measure for the state to ensure the rapid, sustained and healthy development of the national economy. Since the construction of the first-class highway from Zhengzhou to Xinxiang in our province began in the mid-1980s, we have accumulated more than ten years of experience and lessons in the construction of high-class highways. As of 1998, 466 kilometers of expressway has been built. As far as the engineering quality is concerned, there are many unsatisfactory places, and there are some quality problems to varying degrees. As far as the quality of highway construction in the whole province is concerned, there are still some common quality problems, such as insufficient subgrade compaction, subgrade subsidence, poor pavement smoothness, bump at the bridge head, early pavement damage and poor appearance quality.
Engineering construction is a system, and there are many factors that affect the engineering quality. The superior policies, technical specifications, decision-making ideas, construction technology, management level, work quality and construction behavior of design, construction, supervision, owners and supervision units are closely related to the project quality. The following is an analysis of several main reasons:
First, the current work of construction projects is hasty and not deep enough, which leads to decision-making mistakes.
Highway construction projects are generally large in scale, and its construction process is a labor, capital and technology-intensive production process. Different from other commodity production, they have large scale, large investment, long production cycle and long service cycle. Therefore, overall planning and scientific decision-making are very important, and it is necessary to scientifically evaluate the necessity, technical feasibility, economic rationality and macro and micro economic benefits of the project. If the project is not properly established, the decision will not be thorough. First, the scale is small and the standard is low, which can't meet the requirements of design traffic volume and design life. Second, the scale benefit of expressway can't be brought into play in advance by investment and reconstruction. Second, unreasonable route selection will cause inconvenience to driving, increase driving distance, cause great waste and not meet the needs of economic development; The third is the comparison and approval of major technical schemes, construction techniques and main materials. If the selection is improper, it will cause hidden dangers to the project quality. For example, due to various reasons, the design standard of Zhengzhou-Xinxiang first-class highway in our province has been artificially lowered, with low highway grade, low subgrade height, many crossings and mixed traffic, which greatly reduces the use function. Traffic congestion, slow driving speed, hidden dangers in driving safety and water accumulation in the passage bring inconvenience to normal traffic and people's lives. At that time, it was reduced from expressway to first-class highway, with less investment of 50 million. At present, in order to improve the standard to the level of expressway, the investment is about 5. 1 billion yuan.
Second, lack of design experience.
Design is the soul of engineering construction and the leader of engineering quality, which depends on the design quality first. The preliminary work of highway construction project is very complicated, from planning, five projects, feasibility study, project evaluation, design documents, bidding documents, contract terms and specifications to the implementation of bidding projects, the cycle is long. Compared with developed countries, the design of high-grade highway construction in China is still in its infancy. Foreign highway construction projects have clear design and industrial policies, perfect laws and regulations, reasonable design procedures, rich experience in evaluation institutions, numerous design talents, complete and rich project libraries, advanced design equipment and software, a design cycle of more than 20 years and high design quality. Until now, the project library has not been established, and the design tasks are basically one after another. We can't and don't have time to compare and choose multiple projects and schemes, and we don't have this condition to ensure perfect design, so there is a certain gap. From the perspective of the whole province, the design of waterproof and drainage and protection engineering of subgrade and pavement of high-grade highway is too simple at present, lacking experience in traffic engineering, large bridges and tunnels, environmental protection and landscaping. There are too few units with design qualification and experience in each city.
Third, lack of experience in construction management.
Due to the fragmented administrative management system and different sources of funds, the project management mode and level of construction projects are very different, and the construction market is far from standardized management. Generally speaking, key large-scale projects, World Bank loan projects and projects that leaders attach importance to are better, while small and medium-sized projects and local financing projects are not standardized.
The unreasonable management system and irregular management of highway construction market are one of the main reasons that affect the quality of highway construction. The project legal person system, bidding system, supervision system and contract management system of construction projects have not been fully implemented. Some projects have not implemented the project legal person system and contract management system; Some projects do not implement the supervision system, but are still internal supervision or supervision under the leadership of the headquarters. The level of supervision is not high and the intensity is not enough; Some construction projects do not strictly implement the bidding system, some do not bid, some negotiate bids, and do their own projects. There are also self-designed, self-constructed, self-supervised, self-accepted and self-supported "five-self" projects.
The owner's project management ability is not good and he has no experience in large-scale project management. Some owners are temporary headquarters composed of personnel deployed by relevant units, with temporary, loose and short-term ideas, and their quality awareness and contract awareness are correspondingly weak. At present, the situation is not optimistic, and it cannot be solved under the condition of many projects.
There are no strict requirements for the qualifications of design, construction and supervision units. Some projects have unqualified qualifications, leapfrog contracting tasks, and on-site personnel and equipment are inconsistent with the bidding documents. Some even have no qualifications to enter the construction market.
Many projects in our province have not achieved reasonable cost, reasonable construction period and reasonable bidding. It is necessary to adhere to reasonable pricing and prevent vicious competition in the construction market, but it is common to win the bid at a low price and at a low price now; The lowest bid price shall be the lowest reasonable bid price for bank loan projects. However, in our current environment, bidders compete excessively and bid too low, which makes the effective control measures of the World Bank invalid. For example, some tender prices of Luo Zheng Road and Luosan Road are only about 60% of the pre-tender price. Many contractors plan and manage the bidding for the purpose of winning the bid, and the construction is undertaken by the engineering department. There is a big planned economy component in this. Owners do more with less money, and contractors generally want to settle accounts first, not afraid of losing money, and afraid of not winning the bid. As the saying goes, a clever woman can't cook without rice, and low prices can't produce high quality. One of the signs of high-quality projects is that the funds are fully in place, and the saving of winning the bid at a low price is an illusion. In the implementation stage of the project, the contractor will try his best to make up for the losses caused by the low price, which will make the quality managers unable to guard against and lay a deep hidden danger for the project quality.
Fourth, the contractor lacks experience in high-grade highways.
In high-grade highway projects, some contractors have almost no experience in high-grade highway construction, and some contractors in the winning railway department have never worked on highways. They do not have proper road construction machinery and equipment, nor do they have enough management personnel. This is a difficult problem in quality management, and it is easy to have problems without experience. Some engineering contractors do not have enough organizational preparation, technical preparation, material preparation and site preparation in the early stage of construction, and their abilities in construction operation organization management, construction schedule management, construction scheduling management, site management and technical data management are insufficient or not in place, which leads to project management being in a chaotic state and unable to guarantee project quality.
There are three situations in which the construction strength is insufficient: first, there is no strength investment; Second, the difficulty of the project is underestimated, or in order to save money, the investment in personnel and equipment in the early stage of the project is insufficient; Third, the division of blocks is too small, and the cost of dispatching personnel and equipment is correspondingly high. To a certain extent, contractors are reluctant to invest.
Some projects are subcontracted to varying degrees. Due to the lack of strength, the contractor subcontracts the project in order to transfer the project risk and earn management fees, or to take care of the relationship. Some turned a blind eye to the separated projects, and some even subcontracted at different levels, which caused many hidden dangers of project quality and made it difficult to control the project quality.
Five, the main materials and equipment of engineering construction can not meet the requirements.
The quality of raw materials is the basis of engineering quality, and only good materials can produce good quality. The raw materials used in engineering construction are not purchased and allocated by the government, but are generally purchased by the contractor himself, especially the local material selection range is very small. There are many reasons why some raw materials used can't meet the requirements of the specification. First, due to the rapid construction progress, many sources of materials, insufficient inspection equipment and personnel, material inspection can not keep up; Second, in order to reduce the cost, artificially lower the material standard; Third, poor yard management, secondary pollution of materials or lower standards; Fourth, material suppliers resort to deceit; Fifth, some materials are out of touch with use; Sixth, some materials, such as asphalt, the quality of domestic asphalt is not up to standard, the import price is high, and foreign exchange is needed, resulting in a situation that it is not used. Most local materials, such as stone, lime and sand, are mainly processed on a small scale, and there are no corresponding production standards, norms and procedures for industrial production. The grade, specification, gradation and material quality of materials are unstable, and there is no quality guarantee. In engineering, they have to be used due to factors such as construction environment, price, transportation distance and external intervention. For example, in the later period of Anxin Road, the construction period is tight and the demand for road stones is large. Even if the quality of stone in Xiaoshi Factory is higher, it is in short supply, which is a factor that the quality of grass-roots can not be well controlled.
Mechanized construction in highway construction is the premise of ensuring engineering quality. The past tactics and manual operation methods are far from meeting the needs of highway construction and development today. The mechanization level of construction engineering is measured by mechanization degree, technical equipment rate, equipment integrity rate, machinery utilization rate and mechanical operation correctness. The subgrade adopts heavy vibration compaction machinery to ensure the compactness; The quality of the mixture can be guaranteed by using lime-soil field mixing, automatic metering and automatic feeding of asphalt and cement mixing equipment; Paving equipment automatically leveling, preloading, ironing, to ensure the smoothness of the road; The contractor's drilling rig, bridge erecting machine and concrete pouring equipment can ensure the construction quality of the bridge; The advanced equipment in the prefabrication yard ensures the quality of prefabricated components; The field test equipment is complete, the accuracy can reach *, the measurement is accurate, and the test quality is guaranteed.
The contractor's construction site mechanical equipment, especially large-scale equipment, can meet the needs of all stages of construction, and the quality of the project can be guaranteed, otherwise it is difficult to achieve high-speed, high-quality and efficient projects. At present, most construction enterprises in our province lack mechanical equipment, so it is difficult to be competent for the construction of high-grade highways. In some large state-owned enterprises on expressways, machinery and equipment still cannot meet the construction needs. For example, some domestic asphalt mixing equipment is unstable in controlling material gradation and asphalt-aggregate ratio, which can't meet the design requirements. In the accelerated situation, there are fewer and fewer enterprises with strong construction strength, and the shortage of qualified large-scale equipment will be an important reason for poor quality.
Six, the quality management system is not perfect
The second-level quality control system of "government supervision, social supervision and enterprise self-inspection" for highway construction in our province needs to be improved, and the normal operation of the third-level quality control system needs a certain time and process.
L, the strength of the province's supervision team is insufficient, the quality is low. The number and quality of existing supervisors in our province are far from adapting to the development of high-speed, large-scale and high-standard transportation infrastructure. Before 1996, there were only 95 supervision engineers in the whole province, which has been greatly improved since 1996, but it is still insufficient compared with the total number of personnel needed for normal supervision work, and most of them are in other positions and do not directly engage in supervision work.
Some supervision units are not standardized, and the new supervision units lack supervision experience and supervision experience. Some supervision units do not meet the relevant requirements, some leapfrog to undertake supervision tasks, some attach importance to economic benefits, ignore the quality of work, seriously affect the quality of supervision work, some only send a few supervision personnel to stay, and some are temporarily hired; The main factors causing this situation are: first, the proportion of external employees is too large, and the external supervision of general engineering projects accounts for more than 60% of the total number of employees, and some accounts for a higher proportion; The composition of these personnel is unstable, and it is difficult to improve their quality only by not teaching. They lack mutual restraint and trust, and their confidence is not firm. It is difficult to establish the concept of high standards and strict requirements. Second, the training of supervision business is not enough, and training is neglected in some places, especially for external supervision. As soon as the project starts, it will be started, and when it is completed, it will be dissolved, which makes the supervision work stay at a low level. Third, the qualification requirements for external supervisors are not strict. Some supervisors are from the departments of water conservancy, railways and forestry, as well as from other industries. Fourth, individual external supervisors only regard supervision as a means to earn money and seek personal gain, and their work is perfunctory; Some of them stand in the same position as the construction unit, and there are measurement payment and detection data fraud in the process of project supervision.
The supervisor's certificate holding rate is low. For example, there are 1 18, 120 and 55 supervisors in Zheng-Luo, An-Xin and Zheng-Xu expressways respectively, of which 35, 25 and 12 have received supervision engineer training (others have received pre-job training), accounting for 29.7% respectively. The number of people holding the supervision engineer certificate of the Ministry of Communications is 1 1, 10 and 2, accounting for 9.3%, 8.3% and 3.6% respectively. The comprehensive reflection is that the three major controls of project quality, progress and investment have not achieved the expected results.
2. The restriction mechanism of the supervision team is not perfect. The government transportation authorities mainly manage the supervision market macroscopically, mostly managing the qualifications of supervision units and personnel, lacking the means to dynamically manage the behavior of supervision units, the operation of supervision work and the effectiveness of supervision work, and the restraint mechanism of supervision units in terms of laws, regulations, administration and economy is not perfect.
3, government supervision network, some construction units, construction unit leaders and managers, lack of understanding of the importance of engineering quality supervision, resulting in quality supervision work is difficult.
4. The quality inspection equipment and means of all parties in quality management are not perfect. Most design, supervision, construction and supervision companies' testing equipment, testing means and technical force can't meet the needs of quality inspection, and some of them are far from the actual requirements, which directly affects the depth and intensity of quality management.
Seven, grasp the project quality out of control caused by the time limit for a project.
The construction period of the project is scientifically arranged on the basis of accurate calculation. In network planning, the whole planning task can be closely organized according to the objective laws of construction, resources can be rationally allocated, and time and space can be closely connected and coordinated. The key lines control the planned progress of the project, and the planned progress is affected by various links and factors in the construction process. The schedule can be adjusted according to the progress of the project. If we violate the normal construction rules and blindly advance the construction period, it will bring great difficulties to quality control, even difficult to control. Speed and quality are contradictory. If you pursue speed, you may ignore quality, and grabbing work is the enemy of engineering quality. There are two situations to catch up with the construction period: one is to rush to open to traffic in advance. Second, work was rushed in the later stage of the project, and the contract period was not advanced. Because the pre-project construction funds are not in place, the planned progress is seriously lagging behind. For example, Anxin Road has a three-year construction period, and the workload completed in the first two years is only 5 1.4%, while in 1 1 month of1997, 48.6% of the workload has to be completed.
If there is a problem, study it and finally solve it. It should be said that our construction market is becoming more and more standardized, with laws to follow and rules to follow. Now the key is how to do it. The director of Hebei Provincial Communications Department put it very well: "We can't bear the responsibility for quality problems, we can't afford to lose money, we can't afford to lose public opinion, we can't afford to lose our conscience and delay our career. If everyone has this kind of quality anxiety and really does it seriously, we can prevent common quality problems and improve quality.
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