In order to facilitate candidates to understand their exam situation in a timely manner and make good work or study arrangements for the next step, Dali Education will promptly organize the latest information on the answers to the real questions after the first-level construction

　　【Answer】D

　　【Analysis】Asphalt used in asphalt mixture should have the following properties:

　　(1) Has appropriate consistency: characterize the adhesion size, that is, the viscosity under certain temperature conditions.

　　(2) Has great plasticity: expressed in "delay", that is, the ability to deform under a certain temperature and external force without cracking.

　　(3) Have sufficient temperature stability: that is, asphalt is required to be low in temperature sensitivity, not soft in summer, and not brittle in winter.

　　(4) Has good atmospheric stability: strong resistance to heat, light, and anti-aging.

　　(5) Have good water stability: strong water damage resistance.

　　2. Compression of densely graded asphalt concrete mixture should be preferred for rolling with ().

　　　A. Steel wheel roller

　　　B. Heavy-duty tire roller

　　　C. Vibration roller

　　　D. Double-wheel steel cylinder roller

　　D. Double-wheel steel cylinder roller html l5

　　　【Answer】B

　　　【Analysis】Recompression of densely graded asphalt mixture should be made with heavy-duty tire rollers for rolling to increase the water permeability of the road surface. The total mass should not be less than 25t

　　　3. When tensing multiple prestressed ribs at the same time, the () of each prestressed rib should be consistent.

　　　　　　　　　　　　　　A. Length

　　　　B. Height position

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　� During the tensioning process, the movable beam and the fixed beam should always be kept parallel.

　　4. During the process of applying steel sheet piles , the indicator that should be checked at any time is ().

　　　A. Apply the resistance of the earth friction

　　B. Pole perpendicularity

　　c Groundwater level human

1　　D. Position of pile sinker

　　　【Answer】B

　　[Analysis] During the steel sheet pile construction process, the position of the pile should be checked at any time whether the pile position is correct and whether the pile body is vertical, otherwise it should be corrected or pulled out and re-drilled immediately.

　　　5. When the wet joint design of the continuous beam is simply supported first and then the wet joint of the continuous beam requires that prestress be applied, the system conversion time is ().

　　　A. The temperature should be lower in a medium period

　　　B. When the wet joint pouring is completed

　　　C. When the prestressing is completed

　　D. Prestressed pore slurry When the body reaches strength,

　　【Answer】D

0　　【Analysis】Wet joints should be prestressed and pore grouting according to the design requirements; after the slurry reaches strength, temporary support should be removed immediately, and the system conversion should be completed by connecting the specified procedures of the design. Temporary support of the same beam should be removed at the same time.

　　6. The use of high-pressure rotary spray grouting method in () will affect its reinforcement effect.

　　　A. Silty soil

　　B. Plain filling soil

　　C. Hard clay soil

D. Gravel soil

　　【Answer】C

　　【Analysis】The hard clay soil and soil layers contain more large-sized blocks or organic matter. When the groundwater flow rate is large, the high-pressure jet grouting effect is poor.

　　7. Among the following soils, the one that is suitable for prefabricated caisson drainage and sinking is ().

　　　A. flow sand

　　　B. Stable clay soil

　　　C. Containing cobbles layer

　　　D. Silt layer

　　　【Answer】B

　　8. Set compensator in thermal pipelines. Only the axial movement of the pipelines on both sides of the valve is ().

　　　　　　　　　　　　A

　　　　A

　　　　　A

　　　　　Addressing of digital level meter, the order of fourth-level level observation should be ()

　　　A. Back→front→front→back

　　　B. Front one after one after one after one after One front

　　　C. Next one next one front → front

　　　D. Before → front one next one after

　　【Answer】C

　　【Analysis】The third-class digital level measurement observation order should be the next one before

　　　　　　　Before → back; the fourth-class level measurement observation order should be the next one next one before → front;

　　　10. The function of laying reinforced mesh on the surface of volume concrete is ()

　　　A. Improve the compressive strength of concrete

　　　B. Prevent concrete sank cracks

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　� tml3

　　　D. Prevent concrete from shrinking and cracking

　　　【Answer】D

　　　【Analysis】In design, laying crack-resistant reinforcement mesh on the surface of concrete can effectively prevent dry cracks when concrete shrinks.

　　11. The project that is organized by the general supervision engineer to conduct acceptance by the project leader of the construction unit and the project technical quality leader is ()

　　A. Inspection batch

　　B. Sub-project

　　Collection

　　Collection

　　C. Sub-project html ml5

　　　D. Unit project

　　[Answer] C

　　[Analysis] Branch (sub-branch) project should be organized by the general supervision engineer to organize the project leader of the construction unit and the project technology and quality leader, etc. for acceptance.

　　　12. The correct statement about drainage pipeline repair and update technology is ()

　　　A. The construction speed of lining method is fast, and the cross-section is damaged is small

　　　B. The length of the left pipeline repair of the spraying method is not limited

　　C. For the pipe expansion method, the left straight pipe bend can be used

　　D. The pipe breaking and ejection method can be used in hard strata. It is less affected by geology and is

　　　 [Answer] D

　　　【Analysis】Option A is wrong, the lining method is simple to construct and fast, and can adapt to bend pipes with large radius of curvature, but there is a large loss in the cross-section of the pipe. Option B is wrong. The spraying method is suitable for repairing various pipes with a pipe diameter of 75~4500mm and a pipeline length of less than 150m. Option C is wrong. Extrusion of broken pipes is also called the pipe burst method or the pipe expansion method. Its disadvantage is that it is not suitable for the replacement of bent pipes and .

13. Regarding the construction of bentonite waterproof blanket , the correct statement is ().

　　　A.Waterproof blanket When laying along the slope, a certain amount of margin should be reserved at the top of the slope

　　　B. The waterproof blanket should be distributed in a font shape, and there should be no cross overlaps

　　C. When laying a pipe, cut holes with a diameter greater than the pipe should be inserted into html on the waterproof blanket with a diameter greater than the pipe. 3

　　D. If the waterproof blanket is torn, bentonite powder sealant must be spread to repair

　　　 [Answer] B

　　　【Analysis】Option A is incorrect. After the slope is laid, no less than 2m of bentonite waterproof blanket remaining on the bottom surface. Option C is wrong. The bentonite waterproof blanket is constructed in special parts such as pipes or building columns. First, cut the square with a pipe diameter plus 500mm as the side length, then cut holes with the same diameter as the pipe diameter at the center, and then repair the edges to make it tightly on the pipe; then evenly spread or apply bentonite powder around the pipe at the junction of the pipe and the bentonite waterproof blanket. Option D is incorrect. If there is any tear or other damage, all the bento waterproof blankets should be replaced.

　　14. Regarding the statement that box is imperative ().

　　　A. Drainage measures should be taken to the operation area, and water should not be accumulated

　　B. When the train passes, excavation should not be stopped

　　　C. Closed management is implemented, and non-construction personnel are strictly prohibited from entering

htt ml1　　D. During the process of thrusting, no one shall stay in the iron and column layout area of thrust iron and columns

　　　 [Answer] B

　　　[Analysis] During the train operation gap or avoid the peak traffic period; when the train passes, it is strictly forbidden to work, and personnel should evacuate the excavation surface.

　　　15. Before the concrete pool is tensioned without bonding prestressed tendons, the concrete in the pool wall () should meet the design requirements

　　　A. Compressive strength of the test block with the same condition

　　　B. Flexible strength of the test block with the same condition

　　　C. Compressive strength of standard test block

　　D. Flexible strength of standard test block

　　【Answer】A

　　　　Analysis When tensioning without bonding prestressed tendons, the compressive strength of concrete cubes in the same condition should meet the design requirements.

　　16. The contractor shall issue a claim intention notification to () within days of the claim event ()

　　B.28, construction unit

0　　C.28, Supervision Engineer 3

　　C.28, Supervision Engineer

　　D.14, construction unit

　　 [Answer] C

　　[Analysis] Within 28 days of the claim incident, a notice of claim intention was issued to the supervision engineer.

　　　17. The correct statement about the layout of pipelines in the comprehensive pipeline corridor is ()

　　　A. Natural gas pipes can be laid in the same warehouse as thermal pipelines

　　B. Thermal pipeline can be laid in the same warehouse as power cable

　　　C. 110kv and above power cables should not be laid in the same side as communication cable

　　D. When the water supply pipe enters and exits the comprehensive pipeline corridor, the valve should be laid in the left corridor. tml5

　　【Answer】C

　　【Analysis】Natural gas pipelines should be laid in separate compartments; thermal pipelines should not be laid in the same compartment as power cables; the space required for pipeline exhaust valves, compensators, valves and other accessories for installation, operation and maintenance operations should be reserved for the comprehensive pipeline corridor.

　　18. Geogrid is used for embankment reinforcement, it is advisable to use () and have high strength products.

　　　A. Small deformation, small roughness

　　B. Misconception, large roughness

　　　C. Large deformation and small roughness

　　D. Large deformation and large roughness

　　【Answer】B

　　　[Analysis] Geogrids should choose products with high strength, small deformation and large roughness

　　19. Use a sliding form paver to pave the concrete paver. When the slump of concrete hours, the paving method should be used in ().

　　　　A. High frequency vibration, low speed

　　　B. High frequency vibration, high speed

　　　　　　　　　　　　There is a small slump in concrete, and high speed

　　　D. Low frequency vibration, high speed

　　　　 [Answer] A

　　　　　　　Analysis: Concrete has a small slump, and high frequency vibration is applied, and low speed paving is paved.

　　20. The correct statement about the construction method of subway stations is ().

　　　　　　　A. The cover excavation method can effectively control the surface settlement, which is conducive to protecting nearby buildings

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　The cover excavation method can effectively control the surface settlement, which is conducive to the protection of nearby buildings

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　Prestress applied to the fixed end

　　　D. Large-scale machinery can be used to excavate and produce soil and work

　　　【Answer】A

　　【Analysis】The disadvantage of open-scale excavation is that it has a great impact on the surrounding environment; large-scale machinery cannot be used for the cover excavation method, and special small and efficient equipment is required.

Multiple choice questions

Among the alternative answers to each of the following questions, there are two or more correct answers that meet the meaning of the question, and at least 1 wrong item. No points will be obtained if multiple or wrong choices are selected; if you choose less, each selected option will get 0.5 points.

　　21. The impact of driving load and natural factors on the road structure gradually weakens with the increase of depth, so the requirements for road materials gradually decrease with the increase of depth.

　　　A. Strength

　　　B. Stiffness

　　C. Water content

　　D. Particle size

1　　　　　E. Stability

　　　【Answer】ABE

　　【Analysis】The surface layer is a layer that directly contacts the vehicle and the atmosphere, and bears the driving load (large firming force, horizontal force and impact force), and is also affected by the erosion of precipitation and temperature changes. Therefore, the surface layer should have high structural strength, stiffness, wear resistance, water impermeability and high and low temperature stability, and its surface layer should also have good flatness and roughness.

　　22. The retaining wall that mainly relies on the filling weight on the base plate to maintain the stability of the retaining structure has ().

　　　A. Gravity retaining wall

　　B. Cantilever retaining wall

　　C. Buttress retaining wall

　　D. Anchor rod retaining wall

　　D. Anchor rod retaining wall

　　　E. Reinforced earth retaining wall

　　　【Answer】BC

　　　【Analysis】Cannon-type and buttress retaining walls maintain the stability of retaining structures based on the filling weight on the bottom plate

　　　23. The functions of urban bridge waterproof drainage system include ().

　　　A. Quickly eliminate the bridge area water

　　　B. Minimize the possibility of water seepage to the limit

　　C. Reduce the occurrence of structural cracks

　　D. Ensure no water leakage in the structure

　　　E. Improve the strength of the bridge deck paving layer

　　　【Answer】ABD

　　　【Analysis】Bridge deck waterproofing system: It should be able to quickly remove water from the bridge area and minimize the possibility of water seepage. The urban bridge drainage system should ensure that there is no drip under the bridge and no water leakage on the mechanism.

　　24. The coagulation precipitation of the water feeding treatment process is to remove () from water.

　　　B. Suspension

　　C. Bacteria

　　D. Metal ion

　　　E. Colloid

　　　【Answer】B.E

　　【Analysis】Coagulation precipitation is to use a coagulant agent to precipitate or clarify to remove colloids and swelling matter in water

　　25.Underwater concrete infusion catheters are installed and used, and the items that should be inspected are ().

　　　A. Catheter thickness

　　　B. Watertight pressure test

　　C. Airtight pressure test

　　　D. Joint tensile test

　　D. Joint tensile test

　　　E. Joint compression test

　　　【Answer】ABD

　　　[Analysis] Before installation, a dedicated person should be responsible for inspection. The main inspection items include whether there are holes and cracks in the infusion catheter, whether the joint is sealed, and whether the thickness is qualified. Before use, watertight pressure and joint tensile tests should be carried out, and Yan Jin Yong Pressure should be carried out.

　　26. Regarding the construction of gravity concrete tile. The correct ones are ()

　　A. When the top of the foundation concrete is coated with interface agent , no chiseling treatment shall be done

　　B. It is advisable to pour

　　C. When pouring in blocks, the joints should be parallel to the long side of the cross-sectional dimension

　　　D. The upper and lower layers of chunk joints should be in the same vertical

　　　E. The joints should be made into the form of

　　　[Answer] B.E

　　　　　　　　　Analysis: Before pouring the concrete on the pier, the top of the foundation concrete should be chiseled. When pouring in blocks, the seams should be parallel to the side with smaller interface size, and the seams of adjacent layers should be staggered.

　　27. Regarding the statement of shield receiving, the correct ones are ()

　　A. The soil quality of the hole section before the shield is received should be checked for qualified

　　　B. The shield reaches the working well within 10m of the working well, and measure and adjust the attitude of the shield

　　C. When the shield reaches the working well, the last 10~15 ring pipe segments are tightened to squeeze the ring joints of the pipe segments

　　D. After the host enters the working well, the pipe segment ring and the hole door are promptly Seal the gap

　　　E. Shield posture is adjusted only based on the review results of the hole door position

　　[Answer] ACD

　　[Analysis] The shield posture is manually measured 100m before the shield is penetrated and 50m. Determine the shield attitude control scheme and perform shield attitude adjustment based on the first two review structures.

　　　28. The correct statement about grouting behind the shield wall is ()

　　　　A. Synchronous grouting can fill the shield tail gap

　　　B. Synchronous grouting is used to grout behind the pipe sheet through the hoisting hole of the pipe sheet

　　　C. Secondary grouting plays a role in strengthening the soil around the tunnel

　　　D. Secondary grouting is through the grouting system and the built-in grouting tube of the shield tail grouting

　　　E. In water-rich areas, if the grouting effect is affected, water plugging and grouting will be performed after the secondary grouting is completed. ml5

　　【Answer】ACE

　　【Analysis】The second grouting is used to reinforce the back of the pipe sheet through the hoisting hole of the pipe sheet;

　　29. Regarding the requirements for installation requirements for thermal pipeline valves, the correct statements include ()

　　　A. When the valve is lifted and transported, the wire rope should be tied to the flange

　　　B. When the valve is connected to the pipe in a thread, the valve must be opened

　　C. When the valve is connected to the caliber by welding, the valve must be closed

　　D. When installing gate valve horizontally, valve stem should be within the first half of the circumference

　　E. The plug-in valve should have a 1.5mm gap at the plug-in end

　　　【Answer】ACDE

　　　[Analysis] When the valve and the pipeline are connected by flange or thread, the valve should be installed in a closed state.

　　　30. Regarding the statement about gas pipeline casing that crosses the railway, the correct ones are ()

　　　A. The top of the casing shall be buried deeper than 1.5m

　　　B. The casing should be made of steel pipes or steel bars concrete pipes

　　　C. The inner diameter of the casing should be more than 100mm larger than the outer diameter of the gas pipe

　　D. The gap between the two ends of the casing and the gas pipe should be flexible anti-corrosion, waterproof material sealed

　　E. The distance between the end of the casing and the foot of the embankment should not be less than 2.0m

　　　 [Answer] BCDE

　　　[Analysis] The top of the casing should not be less than 1.7m from the railway shoulder, and should comply with the requirements of the Russian railway management department.

Case (I)

　　Background information:

　　A company undertakes an urban main road renovation and expansion project, with a total length of 3.9km. The construction content includes: road projects, drainage projects, pole and line grounding projects, etc. The road project will widen the existing 28m road width 13.5m on both sides of the main road. A 55m-width urban central avenue was built, and the distribution of the road width is shown in Figure 1.

　　Figure 1 Schematic diagram of the distribution of the lane (unit m)

　　The drainage project takes the d1200mm confluence pipe under the existing roadway as the rainwater pipe. A d1200mm rainwater pipe is built under the non-motor vehicle lane on the west side, and a d400mm sewage pipe is built under the non-motor vehicle lane on both sides, and a new household connection branch pipe and household connection well is built. The sewage originally connected to the existing joint pipe is connected nearby to realize the diversion of rain and sewage. The pole-line grounding project will use existing overhead power cables and communication cables to the pole-line grounding and lay them at the corresponding underground pipe positions.

The following series of events occurred during the project:

1　　Event 1: During the excavation of the road, a gas pipeline crossing the road was found at 0.5m deep under the road surface of pile number K1+350. The project department took protective measures for the gas pipeline during construction.

　　Event 2: When connecting the user branch pipe to the newly built household well, the operators arranged by the project department lacked construction experience. They opened the manhole cover of the existing sewage well and took a slight dissipation treatment and went down the well to operate, causing a worker who went down the well to faint on the spot in the well and was rescued without breathing.

　　　Event 3: The east side of the pile number K0+500~KO+950 is a road cut. Since it is difficult to demolish some houses on the slope, the design uses a gravity retaining wall for vertical support on the slope to reduce land acquisition and demolition.

　　　Problem:

　　　 1. When writing out the municipal engineering renovation and expansion, the design unit will generally lay the safe location of power cables and communication cables, and clarify the principles that must be followed in the construction of the rainwater pipeline and sewage pipeline on the west side.

　　　2. Write down the minimum soil covering thickness of the gas pipeline in Event One, write down the excavation and return to

　　3. Write down the relevant procedures that must be completed before going down the well in Event Two and the safety measures taken to be taken to fill in the rolling process

　　　4. Gravity barrier in Event Three What are the structural characteristics of the wall?

　　　【Analysis】

　　1【Answer】(1) The safe location for laying power cables and communication cables is generally under the sidewalk or in the middle and side belts (2) The principles that must be followed on the construction of the west rainwater pipeline and sewage pipeline: first underground first, then above the ground; first deep and then shallow.

　　　2 [Analysis] The minimum soil covering thickness (road surface to pipe top) of underground gas pipelines should meet the following requirements: it shall not be less than 0.9m when buried under a vehicle roadway; it shall not be less than 0.6m when buried under a non-vehicle roadway; it shall not be less than 0.3m when buried in a place where motor vehicles cannot reach; it shall not be less than 0.8m when buried under a paddy field.

　　(2) Protection measures taken for gas pipelines during excavation: The construction unit should work with the construction unit, pipeline management unit and other relevant units to check the technical information such as pipeline location, and verify the local excavation if necessary. Excavation adopts manual excavation, and gas pipelines are reinforced and protected by measures such as exposure, support or suspension.

(3) Protective measures taken for gas pipelines during backfill: No backfills should be done with frozen soil, garbage, wood and soft substances. The backfill soil on both sides of the pipeline and within 0.5m above the top of the pipe shall not contain debris, bricks and other debris, and shall not be backfilled with ash soil. The stones in the backfill soil above 0.5m from the top of the pipe shall not exceed 10%, the diameter shall not exceed 0.1m, and shall be evenly distributed. When backfilling the groove, the local suspended part of the bottom of the pipe should be backfilled first, and then backfilled on both sides of the pipe. The backfill soil should be compacted in layers, with a thickness of 0.2~0.3m for each layer of false laying. The backfill soil on both sides of the pipeline and within 0.5m above the top of the pipe must be compacted manually. The backfill soil on the top of the pipe can be compacted by small mechanically. The thickness of each layer of false laying should be 0.25~0.4m.

　　　3【Answer】(1) The procedures that must be completed before going down the well include: "Limited (Confined) Operation License", special construction plan approval, and emergency plan approval.

　　(2) Safety measures before operation: Safety technical briefing should be conducted; operators must receive safety technical training and can only take up their posts after passing the assessment; operators must wear gas masks, waterproof suits, protective boots, protective gloves, safety helmets, etc., wear protective belts with ropes, and be equipped with wireless communication tools and safety lights; for gas hazards and bacterial infections that may occur in pipeline maintenance, on the basis of evaluation, ventilation is first carried out, and then testing can only go down the well after passing the test; dedicated personnel are placed on duty in the operation area and the ground to ensure personal safety.

　　4 [Answer] Rely on the wall's self-weight to resist the pressure of soil; the form is simple, the materials are taken locally, and the construction is simple.

Case (II)

Background information:

Background information: A company undertakes a municipal trench project. Among them, the length of the existing roads passing through the town is 75m, and the mechanical hoisting pipe is constructed using =2000mm mud water balance. There is a top pipe working well and one receiving well on both sides of the road. The structural dimensions are shown in Figure 2. Both wells are constructed using the caisson method. Before excavation, pipe well precipitation is used. The design requires caissons to be made in sections and sink in stages, and the height of each section shall not exceed 6m.

　　Figure 2 Cavern section diagram (unit mm) (Note: The numbers in brackets are the size of the receiving well) The cavern construction plan prepared by the project department is as follows:

　　(1) After measurement and positioning, lay a sand cushion layer on the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the edge of the step, and then tie the steel bars, formwork installation, and pour concrete.

1　　(2) After the construction of blade foot parts is completed, each caisson will be constructed according to the process flow of the full bracket → steel bar production and installation → A-B → C → inner and outer bracket reinforcement → pouring concrete.

　　　Problem:

　　　1. How many times does the caisson be made (including the blade foot part)? Write down the process names represented by A, B, and C in the construction plan (2).

　　　2. Write down the principles of concrete pouring in caisson and the areas where vibrating should be focused

　　　3. In the construction plan (3), how to deal with the foot before the bottom seal? After the floor pouring is completed, what conditions should the concrete strength meet before the drain well can be blocked?

　　4. Write out the name of the construction machinery required to mount the bracket; what conditions should the mount staff meet before they can operate?

　　【Analysis】

　　1【Answer】Made in 4 times. A is the supporting inner mold, B is the supporting outer mold, and C is the internal and external mold reinforcement.

　　　2【Answer】(1)) Principles of casting caisson concrete: Concrete should be cast in layers symmetrically, uniformly and horizontally, and the caisson should be prevented from deflecting;

　　(2) Parts that should be focused on vibrating: the dense parts of steel bars and the bottom of the reserved hole should be supplemented with manual vibration to ensure the structure is compact.

　　3【Answer】(1) Use a large stone to cushion the foot of the blade before the caisson is sealed. (2) Only when the strength of the bottom plate concrete reaches the design strength level and meets the anti-flooding requirements can the drain well be sealed and precipitated.

　　　4【Answer】(1) lifting equipment ; (2) Operators should undergo professional training, pass the exam, be certified to work, and should have regular physical examinations. Those who are not suitable for high-altitude workers shall not carry out erection and demolition operations; operators must wear safety helmets, seat belts, and anti-slip shoes.

Case (III)

Background information

In mid-October, a project department won the bid for the second phase of the road renovation project in Southern , with a contract period of 3 months, and the contract project volume is: the road modification part is 300m long and 45m wide. The existing cement concrete pavement is paved with asphalt concrete surface layer and the first phase pavement are connected.The new sewage system was buried 4.8m deep. The old road was built and the pipe buried in the pipe was constructed. The part of the first phase of the level crossing was constructed without grooves. The section was 90m long and connected to the sewage receiving well reserved in the first phase, as shown in Figure 3.

　　Figure 3 Schematic diagram of the crossing of the first phase of sewage pipeline in the second phase of the sewage pipeline (unit: m)

　　The project department has prepared the corresponding construction plan based on the on-site situation: (1) Road renovation part: After conducting a full investigation of the existing cement concrete pavement, the following conclusions are made: ① All existing cement concrete pavements that are damaged and empty will be excavated and re-poured; ② The newly built sewage pipelines are excavated and buried. (2) Construction part of the non-grooved sewage pipe: Set up a working well, and the working well is constructed by open excavation method, and the first phase reserved receiving well is opened to prepare for receiving. The plan was returned after being submitted to the supervision engineer for approval and failed to pass. It was required to be modified before reporting. After careful study, the project department found the following problems:

(1) The damaged and empty parts of the existing cement concrete pavement should not be excavated, and repairs should be carried out first.

　　(2) The construction plan lacks the existing cement concrete pavement as a specific method for laying asphalt concrete as the road base.

　　(3) The location selection and special plans for work wells are missing in the construction plan.

　　　Problem

　　　1. How many methods are there for substrate treatment for the determined damaged and empty areas? What are the methods?

　　　2. When investigating the daily cement concrete pavement, what methods are used to find out the relevant situation of the roadbed?

　　　3. The existing cement concrete pavement is added as the road base layer. What structures need to be adjusted before laying asphalt concrete?

　　4. What requirements should be selected for the position of the working well?

　　　【Analysis】

　　　1 [Answer] There are two methods of substrate processing: one is excavation substrate processing, that is, replacement of the substrate material; the other is non-excavation substrate processing, that is, grouting fills the voids in the evacuated parts.

　　　2【Answer】 ground-penetrating radar .

　　　3【Answer】In order to match the asphalt concrete, the elevation of the inspection well should be adjusted.

　　　4 [Answer] The location selection of the work well should be considered to not affect the ground social traffic, have little impact on the noise and vibration of nearby residents, and can meet the needs of construction and production organizations.

　　　　　　　 case (IV)

　　　Background information

　　A company built a sewage treatment plant project. The water treatment structure is underground structure , the maximum buried depth of the bottom plate is 12m. The design of the water-rich formation requires precipitation of the pipe well and strictly control the changes in the water level elevation inside and outside the foundation pit. There are buildings and pipelines that need protection around the foundation pit. The project department entered the site and started the construction of the cement soil mixing pile water-stop curtain and drilled cast pile enclosure structure. The main structure part adopts the block casting method of unit combination concrete structures for the sedimentation ground, biological reaction tank and clear water tank according to the requirements of the plan, and casting strips are left between the blocks. The design strength of the main part of the concrete is C30, and the impermeability resistance grade P8.

Affected by the delay in demolition, the project implementation progress plan was delayed by about 1 month. In order to ensure that the project is put into use on time, the project department proposed to use a new process in the rear pouring belt part to shorten the construction period. The process was approved by the owner, supervisor and designer and obtained the design change document. The installation quality of the water-stop steel plate of the chamfered wall panel construction joint is the key to affecting the anti-seepage performance of the structure. The construction staff of the project department require the construction team to carry out construction according to the drawings. During the quality inspection, it is found that the installation of the water-stop steel plate is shown in Figure 4.

　　Figure 4 During the quality inspection, it was found that the installation diagram of water-stop steel plates was

　　Concrete pouring is at high temperature in summer. In order to ensure the quality of concrete pouring, the project department communicated with commodity concrete mixing station in advance, and optimized and adjusted the concrete mix ratio and admixtures. The project department has also formulated corresponding measures for on-site concrete pouring in high temperatures.

　　In the precipitation construction plan prepared by the project department, the groundwater pumped from precipitation is recycled and utilized, and the following arrangements are made: - It is used for on-site dust control, and road surface sprinkling and dust reduction: the second is used for on-site greening and irrigation and bathroom washing. In addition, the surplus water volume was overflowed and discharged into the municipal stormwater pipeline network.

　　Problem

　　1. Write down the process name and concrete strength of the post-pouring parts that can ensure the construction period and quality.

　　　2. Point out the errors in Figure 4; write down water-stop measures that can be used in combination with water-stop steel plates to improve the waterproof quality of construction joints.

　　3. Write down the measures to be taken for concrete pouring at high temperatures.

　　4. Is there a need for refilling outside the foundation pit after precipitation in this project? Explain the reason.

　　　5. Supplement the purpose of precipitation recycling of the project department.

　　6. Improve the procedures and measures for precipitation discharge.

　　　【Analysis】

　　　1【Analysis】 expansion reinforcement belt is a technical measure to compensate for shrinkage concrete by pouring at the preset post-pouring strip of the structure, reducing or canceling post-pouring strip and expansion joint , and extending the continuous casting length of the component. It can be divided into continuous, intermittent and post-pouring. Continuous expansion reinforcement belt refers to the quasi-concrete at the expansion reinforcement belt and the tear concrete adjacent to both sides. Intermittent expansion reinforcement belt refers to the simultaneous pouring of concrete at the expansion reinforcement belt and the concrete adjacent to both sides, while the other side is the construction joint; the post-cast expansion reinforcement belt is the same as the conventional post-cast belt. When a continuous expansion reinforcement belt process is used, the construction period can be greatly shortened.

　　【Answer】Continuous expansion reinforcement belt. The design strength grade of the compensated shrink concrete used for post-pouring strips and expansion reinforcement strips should be one grade higher than the concrete on both sides, and its limited expansion rate is not less than 0.0 25%

　　　2 [Answer] (1) The installation direction of the water-stop steel plate is incorrect. The warped surface of the water-stop steel plate is installed in the direction of the water-susceptible surface. (2) In the concrete structure, water stop belts, water-expanded water stop strips and pre-embedded grouting pipes can be used in combination to improve the waterproof quality of construction joints.

　　3【Answer】(1) When pouring water tanks during hot periods, the concrete mix ratio should be replaced in time, and the concrete slump should be strictly controlled. Anti-seepage concrete should avoid construction in winter and hot periods to reduce the occurrence of temperature cracks. (2) Avoid excessive temperature difference between the inside and outside concrete structures. First, the concrete entering the mold temperature should be lowered, and the concrete should not be allowed to heat up at a lower temperature rise point when solidified, thereby avoiding the internal temperature of the concrete from being too high. (3) Control the slump into the mold and do a good job in pouring and vibration. (4) Reasonably set up post-watering strips.

　　4 [Answer] (1) When pouring water tanks during the hot period, the concrete mix ratio should be replaced in time, and the concrete slump should be strictly controlled. Anti-seepage concrete should be avoided in winter and hot periods to reduce the occurrence of temperature cracks. (3) Control the slump into the mold and do a good job in pouring and vibration. (4) Reasonably set up post-watering strips. (3) Control the slump into the mold and do a good job in pouring and vibration. (4) Reasonably set up post-watering strips.

　　5【Answer】Recharge and maintenance.

　　6 [Answer] (1) Procedures: The construction site needs to apply for a "Temporary Drainage License" from the municipal administration department of the people's government at or above the county level, and submit relevant information such as drainage and drainage plan. Measures: The construction site should have drainage ditches and sedimentation tanks, and sewage must be prevented from leaking and outflowing to pollute the ring; discharge into municipal sewage pipelines or rivers in accordance with regulations.

　　Case (V)

　　Background information:

　　A company undertakes a city bridge project, bidirectional six-lane , the bridge deck width is 36.5m, the main bridge is designed as a T-shaped rigid structure, with a span combination of 50m+100m+50m; the upper structure uses C50 prestressed concrete cast-in-place box girder; the lower structure uses solid reinforced concrete piers, the foundation uses 200cm diameter, reinforced concrete drilled piles, and the bridge facade structure is shown in Figure 5.

　　Figure 5 Schematic diagram of the section division of the bridge facade structure and the superstructure of the box beam

　　(Elevation unit: m; Size unit: cm)

　　The construction organization design prepared by the project department is as follows: (1) The superstructure adopts a construction plan for erecting a full-house steel bracket. (2) The upper structure box beam is divided into five types of sections, including ①, ②, ③.4, and ⑤. The section ⑤ is a combined section with a length of 2m; the construction sequence is determined. The segment division of the box girder of the superstructure is shown in Figure 5.

　The following events occurred during the construction process:

　　Event 1: Before construction, the project department dispatched a special person to contact the relevant administrative department for approval of construction occupation.

　　Event 2: During the construction process, affected by the water depth of the main river channel and the navigation needs, the project department canceled the construction plan of the full-tang steel brackets for the ②, ④, and ⑤ sections of the box beams of the middle and upper structures in the original construction organization design, changed the construction plan again, and reorganized a special construction plan expert discussion meeting.

　　Event 3: During the construction period, the river channel will not be opened. During the construction of box girders, in order to prevent the impact of high-altitude operations on navigation under the bridge, the project department took safety protection measures on the high-altitude operation platform in accordance with relevant construction safety management regulations.

　　Event 4: Before the construction of the Helong section, the project department pre-pressurizes the cantilever end of the box beam section ④ and gradually removes it during the pouring of concrete.

　　Problem

　　　1. Point out what are the "relevant administrative departments" in Event 1?

　　　2. In Event 2, write down the construction sequence of the upper structure box beam after the construction plan is changed. (Denoted with the numbers "①~⑤" and "" in the figure)

　　3. In Event 2, it points out the appropriate construction method for the upper structure box beam after the construction plan is changed.

　　　4. When the superstructure is constructed, which major hazardous sub-projects need to be organized to organize expert demonstration?

　　5. In Event 3, it points out what safety protection measures should be taken by the high-altitude operation platform and operators during box girder construction?

　　6. It points out the role of pre-pressure weight in Event 4.

　　【Analysis】1【Answer】Marine management agency and waterway management department where the construction waters are located

　　2【Answer】③→②→1→④→⑤

　　3【Answer】Cannencing construction

　　3【Answer】Cannencing construction

　　3【Answer】Cannencing construction

　　5【Answer】(1) Safety protection measures that should be taken by high-altitude working platforms: railings and dense-eye safety nets are set up around; horizontal safety nets or scaffolding protective layers should be set up under the working platform to prevent high-altitude objects from falling and causing damage; safety warning signs such as height limit, width limit, and speed limit, and night warning lights are set; (2) Operators must wear safety helmets, safety belts, life jackets and other safety protection measures.

　　　6 [Answer] The cantilever is pre-pressurized at both ends and gradually removed during the pouring of concrete so that the deflection at the cantilever end remains stable.

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