First, the characteristics of highway engineering quality management
The implementation of highway engineering construction quality supervision is an important content of highway construction management system reform, and it is an effective method to strengthen quality management, control project cost, improve investment benefit and construction management level. To sum up, the "three systems" management model has basically taken shape.
(A) Three-layer basis for controlling project quality
1, from the design stage to the construction stage, we must strictly abide by the technical specifications and relevant laws and regulations promulgated by the state, which makes the highway engineering quality supervision have laws to follow.
2. According to the specifications and relevant laws and regulations, the General Quality Supervision Station of the Ministry of Communications has formulated the Detailed Rules for the Implementation of Highway Engineering Quality Supervision and Management.
3. In the specific implementation stage, according to the above provisions and combined with the characteristics of the project itself, the business department has formulated a special project supervision and testing method.
(B) Three levels of highway engineering quality management
1. The self-inspection of the engineering contractor is the most basic layer. In the process of construction, the supervision engineer will not accept the projects that fail to pass the self-inspection or are not self-inspected.
2. The quality inspection and process acceptance of quality supervision engineer is the key to control the quality of highway engineering, and it is an all-round, whole-process and all-weather engineering quality supervision process.
3. The government quality supervision department shall conduct quality supervision and spot check on the project.
(C) the three means of engineering quality inspection
The acceptance and evaluation of engineering quality mainly depends on the data obtained from inspection, quantity and measurement. These three methods can give a comprehensive and objective quality evaluation of the project from part to whole, from outside to inside, from raw materials to products.
Second, the key factors of project quality supervision
Due to many factors affecting the quality of highway engineering, project supervision has basically formed a management system and management methods with regional characteristics in highway engineering construction. The basic characteristics of highway engineering construction are long front and wide working area, especially high-grade highway with large engineering quantity, high investment, many influencing factors and difficult management, which requires our supervisors to grasp the key points and prioritize in practical work.
(A) the attention of managers
In recent years, the expressway in our province has developed rapidly, and the competition in the highway construction market is becoming increasingly fierce. However, individual contractors can't adapt to the new situation quickly. In the market competition, they only pay attention to the quantity and progress of project tasks, ignoring the specific project quality. Some projects won the bid at a low price and rushed for the construction period, which directly damaged the integrity of contractors, which required managers to strengthen their supervision.
(b) Improve the quality awareness of all employees.
If a project wants to get the best quality, whether it is the design and construction unit or the project management organization, although the contractor is the key, the quality awareness of all employees is fundamental, especially for the construction unit. Some workers involved in the construction are not well educated, so you may not listen to them. The instillation of quality consciousness should be carried out at different levels and step by step, which will gradually make the often complicated theory easy to understand. Practice has proved that it is useless for contractors to attach importance to quality without supporting quality management methods in construction enterprises, and management is bound to get twice the result with half the effort. Improving the quality awareness of all employees through various ways requires strict control of all aspects of construction, namely, materials, tests, operations, measurements, handover, responsibilities, leadership inspections and means.
Third, the measures taken by the project quality supervision
(A) quality control is the focus of supervision work, quality is the life and soul of the project. The supervision engineer should be familiar with the technical specifications and procedures of highway engineering and contract documents, fully master them, and conduct comprehensive monitoring and management from raw materials, construction technology and construction process in strict accordance with the requirements of technical specifications, enhance the sense of responsibility and initiative, and do the following:
The division of labor should be clear, and the responsibility should go to people. Make a clear division of labor according to the project, especially the key parts such as subgrade earthwork, bridge and culvert structure and pavement structural layers. Do a clear division of labor, each with its own responsibilities, and carry out all-round and whole-process control and management of each working procedure. This will prevent confusion and unclear responsibilities from affecting work efficiency.
Strictly implement the project quality responsibility system, that is, the project manager, chief engineer, quality inspector, technical personnel in charge of the project, senior supervisor, deputy senior supervisor and supervision engineer of the project under construction have all signed the quality responsibility book, established the quality responsibility system, hung engineering warning signs at the construction site, accepted the supervision of the whole society, and signed special responsibility books for weak links such as abutment backfilling. Strengthen regular and irregular inspections. In order to ensure the quality of the project, the bridge and culvert, subgrade, test, office work and contract of the construction and supervision unit are inspected every month.
According to the project management method, the monthly assessment is realized, which is divided into two parts: the construction unit assessment and the supervision unit assessment. The assessment results are across the board, rewarding the excellent and punishing the poor. Organize technical discussions to solve quality hidden dangers, technical problems and common quality problems in construction in time. With the progress of the project, various skills training courses such as project management, supervision, measurement and payment are also held in due course. It has played a positive role in standardizing the project quality and ensuring the overall quality of the project.
1, the main basis of project quality control is the contract terms, technical specifications and design drawings. The design drawings and technical specifications stipulate the quality standards of the project, while the contract terms require the construction unit to carry out the construction according to the material properties, construction technology and allowable deviation indicated in the design drawings and technical specifications. The basic requirement of quality control is to control raw materials and construction process. Therefore, on-site supervision and management should be carried out according to the basis and requirements of quality control.
1) Strictly controlling the incoming quality of raw materials is the basis of engineering quality control. Raw materials are the foundation that affects the quality of highway engineering, so it is necessary to strengthen the inspection and testing of raw materials used, which requires us to carry out continuous sampling and testing before and after raw materials enter the site, which is the basis of quality supervision and control. Once unqualified materials are found, they will be refused entry or use, and hidden dangers affecting quality will be eliminated in the bud.
2) Whole process supervision is the basic method of engineering quality control. The whole process supervision is to control the project quality before, during and after. Pre-control refers to the control in the project preparation stage, such as the review of measurement results, the examination and approval of test data, and the careful scrutiny of construction technology. Process control refers to the control of engineering construction process, such as the handling of emergencies and the supervision of human factors. Post-event control refers to the quality control after the completion of the project, such as the rework treatment of insufficient concrete strength and the finishing that does not affect the internal quality.
I. Prior control
First, supervise the normal operation of the contractor's self-inspection system. The contractor's self-inspection system is the basic link of the three-level quality assurance system of "government supervision, social supervision and enterprise self-inspection", and it is also the key point to ensure the quality of engineering construction.
B. Strictly review the construction report of subdivisional work. Before the commencement of sub-projects, the resident supervision engineer shall review the contractor's commencement report, put forward quality control procedures and instructions applicable to all projects, and all supervisors, contractors and construction personnel shall jointly follow them, carefully review and approve the construction machinery and equipment, construction scheme, building materials and construction lofting, and provide necessary basic information such as lofting measurement, standard test and construction projects.
C. Do a good job in "pre-control" of the project. "Pre-control" refers to the pre-control of the construction quality of the project, that is, to understand and control the possible problems in advance before the project is determined. Before the start of a single project, a technical disclosure meeting should be held in time to meet with the supervisor and the contractor to enhance understanding, analyze the working procedure and refine the main points, so as to eliminate all possible problems in the "bud" state. Without a higher level of supervision, in the process of project implementation, problems cannot be found and solved. Therefore, the resident supervisor should first strengthen the technical assessment and business study of the supervisor, and be sure of the sub-projects to be started. Combined with design drawings and construction specifications, construction supervision tips are given for some key processes to avoid unnecessary rework and waste and improve the one-time qualification rate.
D, strengthen the supervision and supervision of the test and measurement. In all kinds of engineering construction, it is important to check the accuracy of engineering position, elevation size and setting-out, intermediate delivery and completion acceptance. Therefore, in the process of engineering supervision, it is necessary to strengthen the inspection of engineering investigation and detection. The task of test and detection is to effectively control the materials, mixture ratio and strength of various projects to ensure that the physical and chemical properties of various projects meet the specified requirements. Test supervision and inspection shall meet the requirements of materials entering the site according to regulations. Test supervision and inspection work should be carried out in accordance with the provisions of the batch and frequency of sampling test of materials entering the site, and do a good job in various mixture ratio tests, aggregate grading tests, standard compaction tests, structural strength tests, etc. , according to the prescribed frequency to do a good job in the construction process, and do a good job in the project acceptance test. The test data should be scientific, accurate and rigorous to guide the project construction and ensure the effective control and supervision of the project quality.
B, quality control in the process
The first is to strengthen on-site supervision. The essence of supervision work is to supervise and manage the construction process, and the side station is an important part of supervision work. The side station should be able to find out the key points in the supervision process, and the concealed works must be carried out in the whole process, all-weather and all-round, and the construction records should be kept, and the construction process of these hidden parts should be preserved in the form of photos. In the process of standby, we should carefully record the construction progress in the construction process. Some unexpected problems in construction should be dealt with decisively and promptly. For projects that are not hidden, the stagnation point should be combined with inspection, and the stagnation point supervision should find problems, face them squarely, solve them and not hide them.
Second, the earthwork construction quality control. Resident supervision should pay attention to the work of subgrade earthwork test section. Through the construction of test section, special indexes such as matching of machinery and equipment, rolling combination, loose paving coefficient and compaction times are determined, so as to guide the construction. Carefully check the properties of the soil used for subgrade filling, and spot check the maximum dry density, optimum water content, liquid limit, plasticity index and other values. The soil yard that does not meet the requirements of the specification shall not be used for subgrade filling construction, and three sampling inspections shall be carried out, that is, there are "springs" that are not sampled, the water content is too high, and the flatness is poor.
Third, the quality control of pile foundation construction, the construction supervisor should carefully read the relevant engineering geological data in the design documents, and should prompt the contractor to take measures to carefully review the position of the casing, detect the mud proportion, mud consistency and circulation, and must stand by during the whole process of underwater concrete pouring. Strictly control the mixture ratio of concrete, check the use of additives, and measure the buried depth of conduits and wellhead. , and check the slump of concrete. In the process of pouring, the corresponding specimens should be retained according to the requirements of the specification.
Four, culvert masonry engineering quality control, for the stone used as masonry engineering, should ensure no weathering and impurities, thickness should not be less than the specification requirements, color and texture should be consistent, flaky layered masonry, it is strictly prohibited to fill flaky before grouting, grouting method is used for construction. When laying, the mortar should have good workability, and the mortar should be full without leaving gaps. Supervise and urge the contractor to do a good job in jointing and later maintenance.
Fifthly, the quality control of abutment backfill soil, bump at bridge head has become a common problem in highway engineering construction, which is very harmful and difficult to deal with. To solve the problem of bump at the bridge head, we should start from the foundation. First of all, we should control the lime-soil mixing method of backfill soil at the back of abutment. It is required to adopt centralized mixing method to ensure uniform mixing, strictly detect the calcium and magnesium content of lime and the amount of lime after mixing, control the compaction thickness, and supervise according to the compaction times and rolling organization determined by the test.
Sixth, pay attention to the appearance quality of buildings. At present, the quality consciousness is generally improved, and the appearance of structures has become a key factor to measure the quality of concrete, making the appearance of concrete smooth, flat and dense, without missing reinforcement, honeycomb, pitted surface and consistent color. Formwork should require straight joints, no slurry leakage and no formwork leakage. Concrete vibrating should be inserted quickly and put slowly to ensure the vibrating range, vibrating time and vibrating frequency.
C. quality control afterwards.
A. Supervisors should do a good job in sorting and filing office materials. Engineering quality plays an important role. The arrangement of office data should follow the principle of "completeness, timeliness and accuracy", set up a special data archive room independent of the contractor, and formulate corresponding data management methods according to the Archives Law and the Regulations on Engineering Archives, designate special personnel to be responsible for it, with clear classification and detailed contents in the volume. Data should be filed in time.
B, the supervision of concealed engineering is the focus of engineering quality control. Concealed engineering is the hidden point of quality hidden danger and the most difficult to control. It is difficult to control because of its concealment. As a supervision control, the best way is to carry out process control, carefully check every working procedure in the construction process and stand by in all directions, so as to achieve "quick eye, quick mouth and quick action", discover defects in construction in time, eliminate them quickly, avoid the emergence of engineering hidden dangers, and complete independent highway projects or structures.
On-site supervision is an important means of supervision and control. On-site supervision is mainly accomplished through patrol and standby. The supervision engineer should patrol, stand by, sample and inspect every working procedure in the project construction, find problems in time, remind the contractor to take effective treatment measures, control the quality error within the allowable range, and fully ensure the quality of the project construction. Every patrol inspection should be recorded in the supervision log in detail, so as to find relevant engineering data in the future and make a comprehensive evaluation of the whole project quality in time.