1 Key factors of engineering quality supervision
Due to many factors affecting the quality of highway engineering, project supervision has basically formed a governance system and governance 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 work focus and prioritize in practical work.
1. 1 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 robbed the construction period, which directly damaged the integrity of contractors, which required managers to strengthen their supervision.
1.2 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 a construction enterprise, only the contractor attaches importance to quality, without supporting quality control measures, is useless, and control is bound to get twice the result with half the effort. To improve the quality awareness of all staff through various means, it is required that all aspects of construction should be strictly controlled, that is, materials, tests, operation, measurement, handover, responsibility, leadership inspection and means.
2. Whole process supervision
2. 1 Prior control
First of all, we should 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.
Before the commencement of subdivisional work, the commencement notice of subdivisional work must be strictly reviewed, and the resident supervision engineer should review the contractor's commencement notice, and put forward the quality control procedures and instructions applicable to all engineering projects. * * * All supervisors, contractors and construction personnel should follow them together, 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 project.
Do a good job of "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.
Strengthen the supervision and supervision of test detection 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.
2.2 Quality control of things
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.
2.3 quality control afterwards.
2.3. 1 The supervisor should do a good job of 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 independent of the contractor, and formulate corresponding data management methods according to the Archives Law and the Regulations on the Management of Engineering Archives, and designate special personnel to be responsible for it, with clear classification and detailed contents in the volume.
2.3.2 Supervision of concealed works is the key point of project quality control. Concealed engineering is the hidden point of quality hidden danger, and it is also 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, so as to achieve "quick eye, quick mouth and quick action", find out the defects in construction in time, eliminate them quickly, avoid the emergence of engineering hidden dangers and complete independent highway projects or structures.
2.3.3 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, and remind the contractor to take effective treatment measures to control the quality error within the promised range, so as to 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 deal with the whole project in time.