Examination questions of subgrade and pavement detection.
(Volume 06)
Unit name, admission ticket number and score
I. Fill in the blanks (20 points)
1. Considering the needs of construction task, construction management and quality control, the construction project is divided into three levels: unit project, division project and subdivisional project. The evaluation unit of quality inspection score is subdivisional work.
2. Errors include absolute errors and relative errors.
3. The measurement items of earthwork subgrade include compactness, smoothness, longitudinal elevation,
Deflection, centerline deviation, width, cross slope and side slope.
4, asphalt mixture density determination methods include surface drying method, wax sealing method, moisture weighing method,
Volumetric method, etc.
5. The highway plane is reflected by the highway centerline, which is composed of straight curve and circular curve.
And transition line elements.
6, flatness detection equipment is divided into two categories, one kind is profiler, the most commonly used are
3m straightedge and continuous flatness meter; The other is reaction, and bump stacking method is commonly used.
Second, multiple-choice questions (10)
1. The purpose of measuring the skid resistance of pavement is to ensure the B performance of vehicles driving on the pavement.
A, comfort b, safety c, economy d, high speed
2. When the asphalt concrete pavement is completed and accepted, the expressway needs to be tested, and the secondary highway does not need to be tested.
A, compactness b, deflection c, thickness d, and skid resistance.
3. In general, for the same kind of soil, the relationship between the optimum water content determined by heavy compaction test and light compaction test is B. ..
A, w weight >; W is lighter than B, and W is heavy.
4. When measuring the modulus of soil foundation, it is generally required to level it with fine sand. If the fine sand forms a thin integral layer, the measured foundation modulus is greater than the true value B. ..
A, too big B, too small C, and the same D, it's hard to determine.
5. The splitting strength test of cement concrete core samples determines the D strength of cement concrete specimens.
A, compressive b, shear resistance
C. Bending and stretching D. Indirect stretching
6. The basic idea of suspicious data selection method is A, that is, it is almost impossible under the condition of limited repeated testing. If it appears in the test, it means that the test data is unreliable and should be discarded.
A, small probability event b, high probability event
C, small data D, big data
7. Trim 15.45 to three significant figures, and take the integer value as b.
a、 16.0 B、 15.4
c、 15.0 D、 15.5
8. When using Beckmann beam to test the pavement deflection unilaterally, if it is known that the deflection curvature radius of the road section to be tested is 3.0m under the standard axle load, C test is the most suitable.
A, a 3.6m Beckmann beam deflectometer B and two 3.6m Beckmann beam deflectometers.
C, a 5.4m Beckmann beam deflectometer D and two 5.4m Beckmann beam deflectometers.
9. Measurement data with C error cannot be used.
A, system B, randomness C, negligence D, accident
10, the nuclear density meter uses A-ray to measure the material density of pavement structure layer.
A, B, β C, x D, fast neutron
165438+
A is equal to B, slightly deeper than.
C, shallower than D, slightly shallower than D.
12 and a are the position parameters of normal distribution function.
A, standard deviation b, coefficient of variation
C, average d, median
13, other things being equal, the greater the depth of pavement structure, the better the skid resistance of pavement.
A, the stronger B.
C, not necessarily strong. D, the strength is irregular.
14, large retaining wall engineering should be quality inspection and evaluation according to B.
A, subdivisional work b, divisional work c, unit work d, single project
15, the evaluation of pavement structure layer thickness adopts b as the veto index.
A, mean b, lower confidence limit of mean.
C, the upper confidence limit of the average value d, and the single-point extreme value
16, d may cause system errors.
A, misjudgment B, environmental changes
C, interference D, instrument calibration error
17, in the division of engineering and unit engineering score, using the weighted average calculation method to determine the corresponding score value. The general engineering weight is 1, and the main engineering weight is C.
a、 1 B、 1.5 C、2 D、3
18 and c are the main sub-projects of subgrade engineering.
A, drainage engineering b, masonry engineering
C, small bridge d, earthwork subgrade
19, the "evaluation standard" stipulates that the compaction standard of subgrade bed of expressway earthwork subgrade is 95%, and the single-point extreme standard is C.
a、95% B、93%
c、90% D、88%
20. When measuring the rebound modulus of soil foundation with bearing plate in the field, if the total influence quantity is not considered, the rebound modulus of soil foundation will be a compared with the true value.
A, too big b, too small.
C, the same D, too big and too small are irregular.
Iii. Multiple choice questions (10)
1, the factors affecting the skid resistance of asphalt pavement are ABC D.
A, PSV value of stone b, structural depth of pavement
C, road surface humidity d, road surface temperature
2. In the current highway engineering quality inspection and evaluation standard, the representative value of BD is calculated according to T distribution.
A, deflection B, compactness C and 3m directly measure the pavement flatness D and pavement thickness.
3. The commonly used data selection method is ABD.
A, 3 times standard deviation method B, Xiao Wienert method
C, t distribution method d, grab method
4. The following reading AD(0.0 1 mm) may be the correct reading of the dial indicator.
a、 12.5 B、 12.3
250.4 D、 123.0
5. When measuring the anti-skid value of pavement with pendulum instrument, when using rubber sheet ABC, a new rubber sheet should be replaced.
A, the end in the length direction wear more than 65438±0.6mm C, oil pollution.
B, the edge in the width direction wear more than 3.2mm D, valid for more than half a year.
6. In the current highway engineering quality inspection and evaluation standards, BCD is a test item of asphalt concrete pavement.
A, rebound modulus b, compactness c, centerline deviation d, deflection
7. The design deflection value of asphalt pavement is related to ABC.
A, cumulative equivalent axle times b, highway grade
C, the total thickness of pavement structure d, surface type
8.AB C is the test method of static deflection.
A, 3.6m Beckmann beam method B, 5.4m Beckmann beam method
C, automatic deflectometer method D, drop weight deflectometer method
9.AB is a statistical characteristic quantity indicating the degree of data concentration.
A, average b, median
C, range d, standard deviation
10. The random sampling method of highway engineering quality inspection often adopts ACD.
A, simple random sampling B, dense grouping sampling
C, systematic sampling D, stratified sampling
4. True or False (10)
1, the design elevation of new highway subgrade is specified as the elevation of road centerline. ( × )
2. Subgrade soil is most easily compacted under the condition of optimum water content. ( √ )
3. When measuring the anti-skid value BPN of the same pavement with pendulum instrument, the higher the pavement temperature, the greater the BPN value. ( × )
4, subgrade compaction index must be layered detection, but only according to the road bed test data score. (√ )
5, the current "highway engineering quality inspection and evaluation standard" regulation, shoulder engineering should be according to the subentry of subgrade engineering inspection and evaluation. ( × )
6. The solid volume ratio is related to the compaction quality and has nothing to do with aggregate gradation. (× )
7. When the thickness calculation of asphalt pavement structure layer is controlled by tensile stress at the bottom of the layer, it will be completed after deflection acceptance.
This value is less than the design deflection value. (√ )
8, continuous flatness meter method with one-way cumulative value to reflect the flatness. (× )
9. When determining the rebound deflection value in unfavorable seasons, the seasonal influence coefficient should be considered. ( √ )
10, the fine structure of asphalt pavement surface can be characterized by structural depth. ( × )
1 1. When driving at high speed, the influence of fine structure on pavement skid resistance is greater than that of coarse structure. (× )
12, the deviation of the representative value of the base thickness meets the requirements, but when some measuring points exceed the extreme value deviation,
The thickness index was rated as 0. (× )
13, weighing method in water is suitable for I or II asphalt mixture specimens with rough and dense surface.
Density determination, but it is not suitable for density determination of asphalt mixture specimens with water absorption greater than 2%. (× )
14, the embankment construction section is short, and the layered compaction degree should meet the requirements, and the actual sampling number.
Not less than six. (√ )
15, all sub-projects are qualified, and the weighted average score is not less than 85 points, then the sub-project is rated as.
Very good. (× )
16. Full inspection is the limit of sampling inspection, but it is only applicable to limited population and nondestructive inspection.
(√ )
17, range and standard deviation both indicate the dispersion degree of data, but range uses less data information than standard deviation. (√ )
18, when compacted, cohesive soil needs higher water content control than sandy soil. (√ )
19. When Beckman beam is used to detect deflection, both sides can be measured at the same time. However, when analyzing and evaluating the deflection, the deflection measured at both sides should be averaged first, and then evaluated. ( )
20, drying method can't correctly determine the optimal water content of cement stabilized aggregate. (√ )
Five, short answer questions (20 points)
1, please describe the evaluation method of asphalt pavement compactness.
The compactness of asphalt pavement shall be subject to 1 ~ 3 km long section. Representative value of road compaction degree for inspection and evaluation (lower confidence limit of arithmetic mean):
When K≥Ko and all measuring points are greater than or equal to the specified value minus 1 percentage point, the specified full mark can be obtained by evaluating the compaction degree of this section; When K≥Ko, for the measuring points whose measured value is lower than the specified value minus 1 percentage point, the deduction value shall be calculated according to the percentage of the total number of testing points.
When k < Ko, the compaction degree of the road section is evaluated as unqualified and zero.
2. Please describe the test steps of bearing plate in-situ testing the resilience modulus of soil foundation.
(1) Preparation: 1) Pick a point; 2) leveling points; 3) Place the bearing plate and level it; 4) stop at the measuring point; 5) arranging a testing device on the bearing plate; 6) Place the deflectometer.
(2) test: 1) preloading 0.05MPa；; 2) measuring the pressure-deformation curve; 3) calculate that rebound deformation and total deformation under the action of load at all levels; 4) determine the total impact; 5) sampling and measuring water content; 6) Measure the density by sand filling method.
(3) Calculate E0.
3. How is the quality grade of construction engineering assessed?
The quality grade evaluation of construction engineering is controlled by two indexes, namely, the excellent rate of unit engineering and the evaluation value of construction engineering quality.
Excellent rate of unit project (%) =
The engineering quality score of a construction project is calculated according to the Measures for the Completion and Acceptance of Highway Projects.
All the unit projects included in the construction project are qualified, and the quality level of the project is qualified; All the unit projects contained in the construction project are qualified, the excellent rate of the unit project is not less than 80%, the quality score of the construction project is not less than 85 points, and the project quality grade can be rated as excellent; When any unit project is unqualified, the quality of construction project is unqualified.
4. Please describe the main factors affecting the anti-skid performance of pavement and the test method of the anti-skid performance of pavement.
The influencing factors are: pavement surface characteristics, pavement humidity and driving speed.
Test methods include: braking distance method, pendulum instrument method, structural depth method, friction coefficient measurement method, etc.
5. Please describe the measurement items of cement concrete pavement and the corresponding detection methods.
Measurement items include: bending strength, plate thickness, flatness, depth of anti-sliding structure and height of adjacent plates.
Poor, vertical and horizontal seam straightness, centerline plane deviation, pavement width, elevation of longitudinal section and transverse slope.
Corresponding detection methods: core drilling method or beam specimen bending test, drilling method, continuous flatness meter method, sand laying method, ruler measurement, stay wire, theodolite, steel ruler distance, spirit level method and spirit level method.
Six, example calculation (15 points)
1, medium liquid limit clay filling embankment. The maximum dry density ρ dmax = 1.82g/cm3 is obtained from indoor heavy standard compaction test. According to the road grade and ministerial standards, determine the required degree of compaction K0=93% (heavy compaction standard). The test group measured the compaction quality of the completed road section, and the data are shown in the following table. Try to calculate the dry density and compaction degree of each measuring point, and calculate the representative value of compaction degree of this section according to the 95% guarantee rate.
observation station
Digital wet density
(g/cm3) water content
(%) dry density
Compaction (g/cm3)
(%)
1 1.98 14.8
2 1.94 14.6
3 1.97 14.7
4 2.03 15.6 1.76 96.7
5 2.07 16.2
6 2.05 16.3 1.76 96.7
7 1.94 15.8
8 2.04 16.2 1.76 96.7
9 2.02 15.7 1.75 96. 1
10 2.0 1 15.6 1.74 95.6
1 1 1.99 15.4 1.72 94.5
12 2.0 1 15.9 1.73 95. 1
T distribution probability coefficient table
Bilateral confidence level
n 99% 95% 99% 95%
t0.99/
t0.95/
t0.99/
t0.95/
1 1 0.955 0.672 0.833 0.546
12 0.897 0.635 0.785 0.5 18
13 0.847 0.604 0.744 0.494
2. A detection group conducted deflection detection on a completed subgrade, and * * * measured 27 deflection values. The data are as follows: 60,52, 104,110,90,156,224,70, 140,130,70. 2 18, 100,1/kloc-0, 50, 40 (0.0 1mm), please calculate the representative deflection value of this section. (with 2S method, take z? =2.0)。
Seven, analysis and evaluation questions (15 points)
1, the compaction thickness of the cement stabilized macadam base first-class highway is 2 1.5, 22.6, 20.3, 1.7, 1.8, 20.6, 2 1.8 and 22.0 respectively.
(hs=20cm, the allowable deviation of representative value is -8mm, and the allowable deviation of extreme value is-15mm).
(Known: T0.95/4 = 0.438, T0.99/4 = 0.65 1)
2. What problems should be paid attention to when digging holes and filling sand to detect compactness? If the sand consumption of rough surface is not tested in the test, what impact will it have on the test results? Why?