1, Road Quality Index (RQI)
Based on the analysis of the road driving quality index RQI= 10.5-0.75IRI of the experimental forest farm, the road conditions of the experimental forest farm were classified according to the driving quality evaluation standard. Where IRI = a+b*BI, where BI is the detection result of flatness detection equipment; A and b are calibration coefficients. In use, all localities can determine their values according to the actual calibration results. China's current specification "Code for On-site Inspection of Highway Subgrade Pavement (JTJO59-95)" stipulates that there are three methods for measuring pavement smoothness in China: 3m straightedge (TO93 1-95), continuous flatness meter (TO932-95) and vehicle-mounted bump integrator (to T0933-95). In this paper, according to the actual needs, the pavement smoothness of experimental forest farm is measured by continuous flatness instrument. RQI value range is 0~ 10, if there is a negative value, take 0; If the result is greater than 10, take 10.
2. Damage index
The experimental forest farm roads are graded by analyzing the damage index PCI=∑∑DPijkWij, where: c is the initial grading value, which is generally c =100; DPijk is a deduction system of type I injury, J severity and K range. Wij is a weight function when there are many kinds of damage types and severity. Different damage types and severity have different effects on pavement integrity (that is, its attenuation rate) and meeting the requirements of pavement use, so maintenance and reconstruction measures are not needed. It is difficult for the flagship to establish a clear quantitative relationship. Therefore, we can only use the method of combining subjective and objective (similar to the method used in driving quality evaluation) to determine the penalty system DPijk with different damage types, severity and scope. This paper can study the damage, severity, scope and density of pavement.
3. Anti-sliding performance evaluation
The most direct way to measure the anti-skid performance of pavement is to simulate the sliding friction or rolling friction state of wheel load on pavement, and to determine the relationship between friction force and test wheel pressure or test load at this time. Commonly used cutting methods include braking distance method, wheel-holding trailer method, eccentric wheel trailer method and simple pendulum instrument method. The evaluation index of anti-sliding performance is: lateral force coefficient (SFC)/ British pendulum value (BPN)
4、PQI
To evaluate the comprehensive service level of pavement, the pavement quality index PQI = S1XP1+S2XP 2+S3XP 3+S4XP 4 can be used. Among them, S 1, S2, S3 and S4 respectively represent the scores of pavement smoothness, damage condition, bearing capacity and skid resistance; P 1, P2, P3 and P4 respectively represent the weight values of pavement smoothness, damage, bearing capacity and skid resistance. This paper mainly uses the smoothness, damage and anti-skid ability of pavement.
Question 2: What is the latest quality acceptance standard for factory roads? Only roads in the factory (GBJ22-87) can be used. CJJ 1-2008 Code for Construction and Quality Acceptance of Urban Road Engineering and Code for Design of Highway Cement Concrete Pavement can be adopted. For the roads connecting factories in the industrial park, if the compilation basis in the design description does not specify which construction acceptance standard to adopt, GBJ will be adopted as the surface course.
Question 3: How to classify expressways? What are the specific standards? According to the task, function and traffic volume, highways are divided into five grades: expressway, first-class highway, second-class highway, third-class highway and fourth-class highway. Expressway is the main road for cars to travel in different directions and lanes, and all access is controlled. Four-lane expressway can generally adapt to the long-term design life of all kinds of cars converted into passenger cars, with an average annual day and night traffic volume of 2500 ~ 55000 vehicles; The six-lane expressway can generally adapt to the long-term design life of all kinds of cars converted into passenger cars, with an average annual day-and-night traffic volume of 45,000 ~ 80,000 vehicles; The eight-lane expressway can generally adapt to the long-term design life of 60,000 ~ 654.38+million adult buses converted by various vehicles. Other highways are trunk highways, distribution highways and local highways, except that expressways are divided into four grades.
The first-class highway is a road for cars to travel in different directions and lanes, which can generally adapt to the long-term design life of various cars converted into passenger cars. The annual average day and night traffic volume is 1500 ~ 30000 vehicles. Secondary roads can generally adapt to the long-term design life of all kinds of vehicles converted into medium-sized trucks, with an average annual day-and-night traffic volume of 3000 ~ 7500 vehicles. Class III highways can generally adapt to the long-term design life of all kinds of vehicles converted into medium-sized trucks, and the annual average day and night traffic volume is 1000 ~ 4000 vehicles. Four-grade highway can generally adapt to the long-term design life of various vehicles converted into medium-sized trucks. The annual average day and night traffic volume is: 1500 vehicles below two lanes; There are less than 200 cars in a single lane. The choice of highway grade should be based on the highway network planning, proceed from the overall situation, and be comprehensively determined according to the use task, function and long-term traffic volume of the highway. For an expressway, according to the traffic volume and other conditions, different vehicle fatigue numbers or different highway grades can be adopted in sections. Long-term design of highways at all levels: 20 years for expressways and first-class highways; Secondary road 15 years; Class III Highway 10 year; Class-4 highways are generally 10 years, which can be adjusted according to the actual situation. Existing highways that do not meet the requirements of this standard should be rebuilt in a planned way according to the needs and possible principles and the development plan of the highway network, so as to improve the traffic capacity and use quality and make them meet the requirements of relevant grade highway standards. The expressway built by stages must be designed in general, so that the previous project can still be fully utilized in the later stage.
Question 4: What is the standard setting of courtyard road quality? City Urban Construction recently published a book on the quality standards of courtyard roads in residential areas. You can obtain it from the city and county urban construction management unit with relevant documents!
What should I say?
Question 5: What are the standards for rural roads? General rule
In order to strengthen the technical guidance of rural highway construction, ensure the construction quality and improve the investment benefit, according to the technical standards of highway engineering and combined with the actual situation of rural highway construction, the Guiding Opinions on Rural Highway Construction Standards (hereinafter referred to as the Guiding Opinions) is formulated. The "Guiding Opinions" are applicable to rural highway construction and reconstruction projects below the township level (including township level). Special sections of county and township highways in the west can be implemented with reference. Rural highway construction should adhere to the basic principle of "planning first, adapting to local conditions, implementing step by step according to one's ability", take the road of sustainable development, rationally utilize land resources, pay attention to environmental protection, and improve rural traffic and production and living environment in combination with comprehensive improvement of villages and towns. Rural highway construction standards should, in principle, implement highway engineering technical standards. Due to economic, topographical, geological and other natural conditions, it is difficult to implement the road section (hereinafter referred to as the restricted road section), which can be implemented with reference to this guidance after technical and economic demonstration and approval. However, when conditions permit, it should be rebuilt as soon as possible to meet the standards of graded highways. Rural highway sections that do not meet the grading standards stipulated in the technical standards for highway engineering shall not be included in the statistics of graded highways. The design traffic volume forecast of rural roads should comply with the relevant provisions of Technical Standards for Highway Engineering, and it is suggested that the design traffic volume of Grade IV roads should be predicted according to 10 year.
Edit the control elements in this paragraph.
Passenger cars are used as standard models for the conversion of traffic volume in rural highway design. Except for restricted sections, the design speed of rural roads should be implemented in accordance with the relevant provisions of highway engineering technical standards, and it is suggested that the design speed of restricted sections should be controlled at not less than10 km/h. When the traffic volume of different sections changes greatly, different standards can be adopted to implement it in sections. Transition sections should be set between sections with different design speeds, and the change points should be selected where the driver can clearly judge the change of road conditions, and warning signs should be set up. A route should adopt the same clear height, generally not less than 4.50m, which can be appropriately reduced after technical and economic argumentation, but it should meet the transportation needs of local rural roads.
Edit this route
general clause
1 Route design should combine the topography, landforms, geology and hydrological conditions along the route, make route scheme selection and technical and economic demonstration according to factors such as project cost and social environment, rationally use technical indicators, and comprehensively consider the horizontal, vertical and horizontal factors to ensure the continuity and balance of alignment and the safety of driving. 2. Implement the principle of protecting cultivated land and saving land; Less demolition of houses and less relocation of public utility pipelines; Make full use of the old roads, safely use the original bridges and tunnels, avoid major modification or filling and excavation, and prevent the induction of new geological diseases; Convenient for farmers (herdsmen) to travel and serve urbanization; Pay attention to the coordination with the topography, landforms, environment and landscape along the line, and protect the natural ecological environment and cultural relics. 3 Try to avoid crossing areas with poor geology such as landslide, debris flow, soft soil and swamp, and special areas such as desert and frozen soil. When crossing is necessary, the crossing scope should be reduced and necessary engineering and technical treatment measures should be taken.
Width of subgrade
(including the width of driveway and shoulder) shall strictly implement the provisions of Technical Standards for Highway Engineering, in which the width of two-lane pavement in restricted sections shall not be less than 5m, and that of single-lane pavement shall not be less than 3m. If single-lane pavement is adopted, the width of one-sided shoulder should not be less than 0.75m.. One-way streets should be set with wrong lanes within a proper distance. The wrong lane should be located in a favorable position where the driver can see the vehicles between two adjacent wrong lanes. The width of subgrade should not be less than 6.5m, and the effective length should not be less than 20m. In the continuous long downhill section, safety lanes should be set up in places that endanger driving safety. The maximum longitudinal slope in general areas of restricted sections should not be greater than 10%, and the maximum longitudinal slope in areas above 2000m above sea level or in areas with frozen snow should not be greater than 8%. When the maximum longitudinal slope is adopted, its maximum slope length should not be greater than the provisions of the Technical Standard for Highway Engineering. There is an ultra-high curve in the restricted section, and its comprehensive slope value shall not exceed 1 1% (except for areas above 2000m above sea level or snow-covered areas). Parking sight distance, overtaking sight distance, minimum circular curve radius, minimum slope length, maximum slope length of different longitudinal slopes, minimum vertical curve radius and other technical indicators. It can be appropriately reduced through technical and economic argumentation. But there should be no combination of unfavorable factors, and traffic safety facilities should be set up to ensure traffic safety. When using turning curves in restricted sections, we should refer to the relevant provisions of Technical Standard for Highway Engineering (JTJ-97), reasonably determine its technical indicators through technical and economic argumentation, and set up traffic safety facilities and necessary speed limit signs ..... >>
Question 6: Introduction of Municipal Road Engineering Quality Inspection and Evaluation Standard "Municipal Road Engineering Quality Inspection and Evaluation Standard" is an industry standard document approved by People's Republic of China (PRC) Ministry of Construction and edited by Beijing Municipal Engineering Bureau.
Question 7: What are the technical standards of Class III highways? The third-class highway is a two-lane highway for cars. At the same time, tractors, animal-drawn vehicles, rickshaws and other non-automobile traffic are also allowed to use lanes. Its mixed traffic characteristics are obvious, and the design speed can be 40 km/h or 30 km/h.
Two-lane three-grade highway should be able to adapt to the annual average daily traffic volume of 2000-6000 vehicles converted into passenger cars.
According to the task, function and traffic volume, highways are divided into five grades: expressway, first-class highway, second-class highway, third-class highway and fourth-class highway. Expressway is the main road for cars to travel in different directions and lanes, and all access is controlled. Four-lane expressway can generally adapt to the long-term design life of all kinds of cars converted into passenger cars, with an average annual day and night traffic volume of 2500 ~ 55000 vehicles; The six-lane expressway can generally adapt to the long-term design life of all kinds of cars converted into passenger cars, with an average annual day-and-night traffic volume of 45,000 ~ 80,000 vehicles; The eight-lane expressway can generally adapt to the long-term design life of 60,000 ~ 654.38+million adult buses converted by various vehicles. Other highways are trunk highways, distribution highways and local highways, except that expressways are divided into four grades. The first-class highway is a road for cars to travel in different directions and lanes, which can generally adapt to the long-term design life of various cars converted into passenger cars. The annual average day and night traffic volume is 1500 ~ 30000 vehicles. Secondary roads can generally adapt to the long-term design life of all kinds of vehicles converted into medium-sized trucks, with an average annual day-and-night traffic volume of 3000 ~ 7500 vehicles. Class III highways can generally adapt to the long-term design life of all kinds of vehicles converted into medium-sized trucks, and the annual average day and night traffic volume is 1000 ~ 4000 vehicles. Four-grade highway can generally adapt to the long-term design life of various vehicles converted into medium-sized trucks. The annual average day and night traffic volume is: 1500 vehicles below two lanes; There are less than 200 cars in a single lane. The choice of highway grade should be based on the highway network planning, proceed from the overall situation, and be comprehensively determined according to the use task, function and long-term traffic volume of the highway. For an expressway, according to the traffic volume and other conditions, different vehicle fatigue numbers or different highway grades can be adopted in sections. Long-term design of highways at all levels: 20 years for expressways and first-class highways; Secondary road 15 years; Class III Highway 10 year; Class-4 highways are generally 10 years, which can be adjusted according to the actual situation. Existing highways that do not meet the requirements of this standard should be rebuilt in a planned way according to the needs and possible principles and the development plan of the highway network, so as to improve the traffic capacity and use quality and make them meet the requirements of relevant grade highway standards. The expressway built by stages must be designed in general, so that the previous project can still be fully utilized in the later stage.
Question 8: The quality standard of road lighting usually adopts the specified average illuminance and uniformity of road surface. The unit of the former is lux, that is, a bright luminous flux is evenly distributed on the horizontal irradiation area per square meter. The latter is the ratio of the minimum horizontal illumination to the average horizontal illumination. In fact, the brightness distribution of the road surface is very different from the illumination distribution. Using road illumination as road illumination index can not give the real situation of visual perception conditions. Therefore, the International Commission on Lighting suggested that the quality of road lighting should be measured by four indicators: road brightness, uniformity, glare and inducement. Brightness is the amount of light reflected per unit area of pavement, and the unit is cd/m2. Uniformity is the uniformity of pavement brightness distribution. The uniformity affecting the driver's visual comfort is equal to the ratio of the minimum brightness to the average brightness of the road surface on the driving line. Even if the average brightness is high and the brightness distribution is uneven, it is difficult to find obstacles with great difference between light and shade. Glare is a phenomenon that strong light shines directly on the driver's eyes, making him uncomfortable, causing visual obstacles and unclear sight. The degree of eye discomfort caused by glare is evaluated by glare index G, which represents subjective feelings. Recommended by the International Commission on Lighting: G= 1, which is unbearable; G=3, there is interference; G=5, allowable limit; G=7, relatively satisfactory; G=9, no effect. Glare is related to the brightness of the light source, the angle between the line of sight and the light source, and the average brightness of the road. Guidance is to inform the driver of the line shape, ups and downs, intersections and traffic separation of the road ahead through lights. The International Commission on Lighting suggested that the road surface brightness of urban main roads and expressways should be 2cd/m2, and the longitudinal uniformity should be 0.7, G=6. Japan adopts road brightness as road lighting index. Most countries, such as the United States, still use illuminance as the road lighting standard. Illuminance and brightness can be converted to each other. The brightness of point P on the road surface is equal to the illuminance of the point multiplied by the brightness coefficient of the point.
Question 9: What is the representative value of highway engineering quality inspection and evaluation standard? The representative value is calculated by formula, using mean square deviation and average value. The calculated representative value should be greater than the qualified value, and each data should not be less than the extreme value to be qualified. You can look at the quality inspection evaluation criteria. For example, if six compaction points are detected, the final calculated representative value is 98, which must be greater than the specified qualified value, and the value of each of these six compaction points cannot be less than the extreme value of 94.