1 Main influencing factors of municipal road engineering quality

The construction quality of municipal road engineering is influenced by many factors, and the main influencing factors are as follows:

1. 1 Constraints of engineering design on engineering quality. Engineering design is the premise of engineering construction. Without high-quality design, there can be no high-quality project. A project is presided over by an experienced structural engineer, who can choose a suitable design concept according to local conditions, thus making a high-quality design scheme. In addition, the measurement data used in the design is inaccurate, the structural scheme is unreasonable, and there are obvious defects, which will inevitably leave irreparable quality hidden dangers.

1.2 construction organization design and construction technology affect the project quality. The construction unit shall prepare a complete construction organization design and submit it to the supervision unit for review before the construction of the municipal road project, and select the appropriate construction scheme and construction technology according to the actual situation of the project. In addition, municipal roads are often affected by land acquisition, demolition and other factors, so the construction unit should make appropriate adjustments according to the actual changes in construction to adapt to the ever-changing dynamic plan of municipal road construction organization.

1.3 Influence of project participants on project quality. On-site construction personnel and supervision personnel have great influence on the final formation of engineering quality. As a construction technician, you should be familiar with the engineering situation, design intent and requirements, construction scheme and construction progress. At the same time, the construction personnel should find the problems in the construction process in time, and actively reflect the situation to the supervision unit and design unit to ensure the smooth progress of the whole construction process.

1.4 Determine the influence of reasonable project cost on project quality. At present, project bidding has been widely promoted in the field of construction engineering, and municipal road projects usually choose construction by public bidding. However, due to the bid evaluation method and the enthusiasm of the construction unit for low quotation, the winning bid price is low, and some even lower than the reasonable cost. In the actual construction process, in order to make profits, quality standards are often lowered and Jerry-built. Therefore, the construction unit should set a reasonable project price limit and choose a reasonable bid evaluation method to effectively improve the project quality.

1.5 Influence of engineering material selection on engineering quality. Municipal road engineering materials are the material basis of engineering construction. Whether the material selection and composition are reasonable, whether the quality is qualified, and whether the transportation and storage are proper will directly affect the quality and service life of the engineering entity.

2 municipal road engineering construction quality control points analysis

2. 1 Formulate a reasonable design scheme

Municipal roads are mostly financed by finance, which may lead to the randomness of quality, progress and target determination. In addition, when designing municipal roads, we should combine the short-term planning and long-term planning of the city, and comprehensively consider the plane layout and the intersection with water supply and drainage, electricity, gas, communication and other pipelines to avoid the phenomenon of rapid line adjustment and pipeline layout conflict. Therefore, the construction unit should maintain good communication and contact with the design unit in the whole design process, coordinate the relationship between the pipeline units, and let the design unit hand over a high-level design scheme as much as possible.

2.2 Improve quality awareness and improve quality management system.

Construction managers are the organizers, commanders and operators of engineering construction, and also the creators of quality. Therefore, in order to improve the construction quality, it is necessary to improve the quality consciousness of construction participants, establish the concept of quality first, improve the comprehensive quality of managers, put people first, mobilize the enthusiasm of employees and enhance their sense of responsibility. In addition, the construction unit should establish and improve the quality management system, clarify the post responsibilities of quality, implement the responsibilities to people, and formulate and improve the post responsibility system and project quality assessment methods. For the project signed by the supervisor, the construction unit shall establish quality responsibility and large-scale structure construction files, and clarify the quality responsibility.

2.3 Strengthen the control of construction materials

The performance of materials largely determines the quality and life of the project, so the use of materials should follow strict approval procedures. The supervision of engineering materials by engineering quality supervision departments should run through the whole process of engineering construction. The construction unit shall establish a strict quality inspection system, and the quality inspector shall correct the quality problems in time. The supervision engineer should also strictly control the supply sources of materials, and inspect, sample, test and retest the materials entering the site to ensure the quality of construction materials.

2.4 Give full play to the role of project supervision

The implementation of project supervision system in municipal construction projects is of great significance to standardize construction behavior and ensure project quality. The construction unit should clearly define the authority and responsibility of the supervision engineer in this process, so that the supervision engineer can carry out his work scientifically, fairly and independently, and supervise according to the drawings. In addition, the site supervision engineer should do a good job in quality monitoring, accurately determine the quality control points, ensure the overall quality of the project, and do a good job in site supervision of the construction process. Found that the construction unit has irregular construction behavior, must be stopped in time, and issued a rectification notice.

2.5 Make a reasonable construction plan and choose the appropriate technology.

2.5. 1 construction scheme

The construction site of municipal roads is often influenced by many factors. It is very important to make a reasonable construction scheme and choose feasible construction technology to ensure the quality and progress of municipal road projects. The construction scheme must be subject to grading examination and approval system, and the existing problems must be revised repeatedly until they meet the national norms and design requirements. In the process of implementation, on-site personnel should monitor and make implementation records. In view of the new problems or situations in the construction process, the construction unit should modify the construction plan in time and formulate procedural system documents to make the implementation of the construction plan under control.

construction technique

(1) subgrade construction quality control. Before filling subgrade construction, tests must be carried out to obtain technical parameters as the basis for this kind of filling construction. Before subgrade filling, the construction personnel should clean up the ground sundries, level them with a grader, then compact them with a roller before filling, and strictly control the loose laying thickness. The quality of layered embankment filling is the key to ensure the quality of the whole subgrade. The loose laying thickness of each layer must be strictly implemented in accordance with national standards, and the next step can only be carried out after each layer is rolled. The excavated subgrade shall be excavated layer by layer from top to bottom according to the design section and slope gradient requirements.

Do a good job of drainage in time after slope excavation to prevent rain from washing the slope.

(2) Quality control of concrete pavement construction. In order to ensure the mix design of cement concrete, the unit cement dosage should not be less than 300kg；; During construction, the slump and water-cement ratio of concrete should be properly adjusted according to different construction conditions; According to the test of aggregate type, maximum particle size, gradation and admixture, the unit water consumption of concrete is determined; Strictly control the cutting time of concrete pavement. Generally, the compressive strength reaches about 10MPa before cutting. After concrete pavement is poured, it should be covered with wet materials in time and watered for maintenance.

3 Common quality defects in municipal road construction and preventive measures

3. 1 Common quality defects of subgrade and prevention measures

In the process of construction, there may be local settlement, embankment instability, subgrade spring, subgrade water accumulation and so on; Earthwork collapse, lateral displacement, overbreak and disturbance occur in excavation engineering; Backfill engineering backfill soil elevation thickness is not dense, uneven subsidence and other sites. In order to prevent the above quality defects, construction and excavation are allowed only after the subgrade, groove center line and sideline are retested and qualified; In the process of excavation, it is forbidden for excavation machinery to walk on the edge of the groove and the support, and the excavated soil should be loaded and transported away in time; Before filling, thoroughly clean the foundation and treat the soft foundation; The cross slope is discharged into the blind ditch or drainage ditch set on both sides of the road, and then discharged into the ponding well through the blind ditch; By setting the drainage layer, the surface water infiltrated into the pavement structure is eliminated in time to prevent it from infiltrating into the subgrade.

3.2 Common Pavement Quality Defects and Preventive Measures

In the process of construction, the construction unit may reduce the amount of cement, resulting in low structural strength, small rebound modulus and low bearing capacity; In addition, the compaction control is not good during construction, and the water stability is not timely. Compaction after the final setting of cement destroys the formed structural strength, which leads to the reduction of structural strength and can not meet the requirements. In order to avoid the above quality defects, the quality of pavement and subgrade structure must be strictly controlled according to the correct construction scheme and suitable construction technology during the construction process. For asphalt pavement, the construction temperature of asphalt mixture must be strictly controlled; After the asphalt concrete pavement is rolled, its technical indicators must be tested according to the requirements of the specification, and the test records should be filled in.

The quality of the project is formed in the process of project implementation, and the omission of any link may cause quality hidden dangers, and the quality of municipal road construction will directly affect the maintenance cost and service life of future urban roads. Therefore, the participants in municipal road engineering construction should make clear the quality responsibility, standardize the quality behavior, make scientific decisions, design and construct carefully, and ensure the construction quality and effect.