Fill in the blanks

1. The indicators used in climate zoning of asphalt and asphalt mixture in China are: high temperature index, low temperature index and rainfall index.

2. The factors affecting subgrade compaction are soil quality, water content, compaction equipment and compaction method. Controlling water content is the key to construction.

3. Pavement structure can be divided into three layers: surface layer, base layer and cushion layer.

4. Asphalt mixture can be divided into dense type and embedded type according to the principle of strength composition.

5. The mechanism of strength formation of calcareous soil is mainly ion exchange, crystallization, pozzolanic action and carbonization.

6. The main failure forms of cement concrete pavement are fracture, frost boiling, dislocation and arching.

7. The parameters that characterize the bearing capacity of soil foundation are resilience modulus E0 and foundation response modulus K CBR.

8. The two cases of slope collapse are landslide and slip.

9. There are contraction joints, expansion joints and construction joints in the transverse joints of cement concrete pavement.

10, the main forms of lawn laying are grass planting, turf laying and tree planting, which can be selected according to specific conditions such as soil quality, slope and flow rate.

1 1. Highway natural zoning is divided into _ _ _ primary zone, _ _ _ secondary zone and _ _ _19 _ _ sub-zone.

12. The evaluation indexes of pavement performance include driving quality, bearing capacity, pavement damage and skid resistance.

13, stress control and strain control are adopted in the fatigue test of asphalt mixture.

14. Dry and wet subgrade types: dry, medium wet, wet and excessively wet.

15, subgrade slope stability analysis method, mechanical analysis method and engineering geology method.

16. The pavement management system is divided into two levels: network level management and project level management.

17. Based on the similarity of pavement structural mechanical characteristics and design methods, the pavement is divided into three types: flexible pavement, rigid pavement and semi-rigid pavement.

18. According to the characteristics of soil particle composition, highway soil can be divided into coarse-grained soil, fine-grained soil, coarse-grained soil and special soil.

19, cement concrete overlay is divided into combined type, direct type and separated type according to the setting method.

20. Retaining wall structure includes wall back, wall surface, wall toe, wall heel and wall back inclination.

2 1, pavement performance mainly includes function, structure and safety.

22. According to the depth of foundation and filling and excavation conditions, subgrade can be divided into embankment, cutting and semi-filling and semi-excavation subgrade.

23. Pavement can be divided into high-grade pavement, secondary high-grade pavement, intermediate pavement and low-grade pavement.

24. The theory of flexible pavement design is the theory of elastic layered system under double circular uniform load.

Second, multiple choice questions

1, which material is used for embankment filling after being treated according to relevant regulations (b loess)?

2. Which of the following drainage facilities is mainly used to drain the pavement water (D-side ditch) that may be stranded in the subgrade?

3. Dry and wet subgrade is determined according to (subgrade soil boundary consistency B)

4. One of the main functions of the following drainage facilities is to reduce the groundwater level within the subgrade (D-seepage ditch)?

5, we usually used to say "lime-fly ash soil" at the grass-roots level belongs to (lime industrial waste residue stability class).

6. Suitable for highway granular base and subbase at all levels is (grade C graded macadam).

7. In order to combine the asphalt surface layer with the non-asphalt material base, the asphalt thin layer poured on the base is called (layer A).

8. Which of the following protection belongs to the indirect protection against scouring along the river bank (D groin)?

9. The slope of a secondary highway is basically stable, and the slope is only slightly washed, which is the most suitable slope protection (B plant protection).

10, the function of asphalt pavement adhesive layer is (d) to make asphalt layer and asphalt layer combine well.

1 1. The following statement about the transverse joint of cement concrete pavement is wrong (c the transverse contraction joint of ordinary concrete pavement should adopt oblique joint).

12, cutting excavation in winter must be (b top-down)

Third, short answer questions

1. Why should the subgrade be fully compacted? How to determine the compaction standard?

Answer: Improve the compactness of filler, reduce porosity, enhance the contact surface between filler particles, increase cohesion or embedding force, increase internal friction, reduce deformation, and provide a good foundation for normal work. 1. Determine the method of adopting standard dry density. 2, meet the requirements of the degree of compaction

2. Briefly describe the purpose of setting up base course on concrete pavement?

It is necessary not only to effectively prevent the scouring phenomenon of pumping mud, but also to improve the comprehensive rebound modulus of foundation and slightly reduce the thickness of concrete slab.

3. Briefly describe the strength formation mechanism and influencing factors of lime stabilized soil?

A: Mechanism: A proper amount of lime is mixed in the soil, which is evenly stirred and compacted under the optimum water content, so that a series of physical and chemical actions occur between lime and soil, thus fundamentally changing the properties of soil. Generally, it is divided into four aspects: 1, ion exchange 2, crystallization hardening 3, volcanic ash 4, and influencing factors of carbonization: soil quality, lime content, water content, compactness, lime age and curing conditions.

4. Briefly describe the main factors of subgrade humidity?

A: Atmospheric precipitation, groundwater, surface water, water vapor condensate, membrane moving water.

5. What are the common subgrade reinforcement facilities?

Answer: Subgrade reinforcement facilities mainly include slope protection, protection and reinforcement of dikes along the river, subgrade retaining works, shoulder reinforcement and wet soft foundation reinforcement.

6. Briefly describe the influence of natural factors on subgrade and pavement?

A: Natural factors mainly include topography, climate, hydrology and hydrogeology, geological conditions and plant cover, which affect the stability of subgrade. The temperature will cause pavement cracking, and the submerged subgrade will be unstable due to the decrease of its strength and stability, causing landslides and other diseases. Subgrade subsidence, erosion, collapse, frost boiling, asphalt pavement looseness, peeling, cracking and other diseases. It is related to the erosion of surface water and groundwater in different degrees.

7. Briefly describe the main contents of pavement structure survey?

Answer: Analyze the pavement structure damage and predict the pavement performance.

8. Briefly describe the formation mechanism and influencing factors of cement concrete strength?

A: Mechanism: In the process of stabilizing soil with cement, various very complicated physical and chemical interactions have taken place among cement, soil and water, which have obviously changed the properties of soil. These functions mainly include: 1, hydration, ion exchange, chemical excitation and carbonization of cement. Influencing factors: soil quality, cement composition and dosage, water content and construction technology.

9. What are the factors that affect the stability of subgrade and pavement?

Answer: The main factors affecting the stability of subgrade are natural factors and human factors. Natural factors are mainly topography, climate, hydrology and hydrogeology, geological conditions, plant coverage and so on. Human factors mainly refer to load, subgrade structure, construction methods and maintenance measures. In addition, there are artificial facilities near the line, such as reservoirs, irrigation and drainage canals, paddy fields and human activities.

10 How to check the stability of general retaining walls?

Answer: 1, calculate physical weight w and arm Zw 2, check anti-sliding stability 3, check anti-overturning stability 4, check base stress and eccentricity 5, and check physical stress.

1 1. Briefly describe the principle of highway natural zoning?

Answer: 1, principle of similarity of road engineering features, principle of regional difference of surface climate, and principle of comprehensive and dominant natural climate factors.

12, briefly describe the main factors affecting the compaction effect of subgrade?

Answer: 1, water content of soil 2, properties of soil 3, compaction 4, temperature during rolling 5, thickness of compacted soil layer 6, strength of foundation or lower bearing layer 7, rolling machine and method.

13, briefly describe the construction technology of lime stabilized base cushion?

Answer: 1. Prepare lime and soil. 2. Mix the mixture as required. 3. Road mixing construction should meet the requirements of paving, mixing and watering. 4. On-site mixing construction should meet the requirements of mixing and paving. 5. shaping. 6. Scroll. 7. curing.

Fourth, summary questions

1. What principles should be followed in the structural combination design of asphalt pavement?

Answer: 1. Meet the requirements of traffic load. 2. Pay attention to the interaction between adjacent structural layers. 3. Appropriate quantity and thickness. 4. It has good stability under various natural factors.

2, 4.5H method to determine the steps of the center auxiliary line?

Answer: 1, determine F point 2, M point 3, calculate B 1, B2 4, determine I point 5, and connect the center of the circle with the extension line of M point.

3. How to determine the thickness of cement concrete pavement slab?

Answer: 1. Through investigation and forecast, determine the initial traffic volume and traffic composition, as well as the average annual growth rate of traffic volume within the design service life. 2. According to the subgrade soil and water temperature, the nature and supply of pavement materials and heavy traffic, the pavement structure section 3 is preliminarily designed. The resilience modulus of subgrade, cushion and base is determined by test 4. The design flexural tensile strength and flexural tensile elastic modulus of concrete are determined by concrete mix design. Calculate the temperature fatigue stress at the midpoint of the edge of plate 6. Calculate load fatigue stress 7. The sum of load fatigue stress and temperature fatigue stress shall not exceed the design bending tensile strength of concrete slab. Otherwise, reset the initial plate thickness.