CSM double-wheel milling construction method

Abstract

The invention relates to a CSM double-wheel milling construction method, and aims to solve the problems of low efficiency, long operation time, limited application range and the like in traditional underground space foundation pit supporting and waterproof curtain construction. The method comprises the steps of survey lofting, trench excavation, trench forming construction and the like. In the grooving construction process, firstly, slurry (the specific gravity is 1.10-1.25) is prepared, the running condition of a groove milling machine is checked, excavation is started, in the process, a gang tool and a milling wheel are cooled and lubricated by injecting the slurry, and the grooving quality is ensured by continuously monitoring groove section parameters. And after grooving is completed, groove walls are cleaned, and double-wheel milling is adopted for secondary groove grinding or a punching pile machine is adopted for hole sweeping so as to ensure the perpendicularity and flatness of the groove walls. The construction method is suitable for sand layers and muddy silty clay, supporting of deep and large foundation pits and construction of water-stopping curtains can be rapidly completed, disturbance to stratums and environmental influences are reduced, the hole collapse risk is avoided, the construction efficiency is improved, and the construction method is particularly suitable for being used in downtown areas and other limited environments.

Description

Technical Field

[0001] The invention relates to the technical field of engineering construction, in particular to a CSM double-wheel milling construction method. Background Art

[0002] The construction of underground foundation pit support and water cut-off curtain generally includes single-wheel milling machine, double-wheel milling machine, rotary drilling and other methods, among which: The disadvantages of single-wheel slot milling machines are that the tool holder wears quickly, the single slot operation time is long, and the efficiency is low; The disadvantage of the double-wheel slot milling machine is that it cannot achieve slot wall construction with small pile spacing and small foundation pit width due to the influence of the double-wheel milling width; The disadvantages of drilling holes with rotary drilling rigs are that the trench width is difficult to control, the trench depth is small, the single trench operation time is long, and the efficiency is low. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a CSM double-wheel milling construction method, which aims to solve the technical problems of long operation time, low efficiency and limited scope of application existing in the existing underground space foundation pit support and water cut-off curtain construction methods such as single-wheel milling machine, double-wheel milling machine and rotary drilling rig hole forming methods.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a CSM double-wheel milling construction method, characterized in that it includes the following steps: S1. Measurement and setting out; Place measurement control points along both ends of the project centerline and set up centerline position stakes at both ends. Determine the construction control line on the trench excavation working surface and the double-wheel milling construction surface according to the edge lines in the design drawings; S2, digging trenches; A hydraulic grab bucket is used to dig the trench. After the trench reaches the designed elevation, a mechanical bucket is used to dig the trench. The soil is unloaded using a single bucket digging and reverse loading method. The cross-sectional dimensions of the trench section are measured for self-inspection in each excavation cycle. S3, trenching construction; Wherein, step S3 specifically includes the following steps: S3.1. Use shale to prepare mud, and the mud density is controlled at 1.10-1.25; S3.2. Check whether the slot milling machine and its cutter and milling wheel are operating normally, confirm that the earthwork in the slot section has been excavated, move the slot milling machine to the location, fix the cutting teeth on the cutter with screws, align the axis, start the slot milling machine, align the cutter with the center point of the axis, slowly cut, and start the milling wheel to start excavation; S3.3, inject the mud generated during the excavation process between the cutter and the milling wheel to cool and lubricate the cutter and the milling wheel. The cutter rotates in the soil and cooperates with the milling wheel to squeeze, rub and shear the soil, breaking the soil and discharging it out of the trough together with the mud; S3.4, CSM double wheel milling machine continuously measures the trench width, trench depth, trench depth deviation, and trench axis orientation of the trench section during trench excavation, and compares them with the trenching parameters. If the allowable deviation is exceeded, corrections are made to ensure the trenching quality and meet the design requirements; S3.5. When excavation reaches the designed elevation, stop construction, remove the cutting teeth, and proceed to the next construction section; S3.6. After the trenching is completed, clean the trench wall by using a double-wheel milling machine for secondary trenching or a punching pile driver to sweep the hole and repeat the trenching process.

[0005] In the preferred solution, in step S2, the side wall area S1 when the bucket is excavating and the over-excavation area S2 generated when the bucket is excavating are calculated, and the groove width S of the slope excavation and the length L of each cycle excavation are calculated according to S1 and S2. The specific calculation includes: Side wall area S1 = H × (c × 1.3 + b) × 1 / 2; Where: c is the width of the bucket slot frame, b is the distance between the bucket teeth, and H is the exposed depth of the bucket teeth; Over-excavation area S2 = S1 × (1 + a1); Where: S1 is the excavation side wall area, a1 is the percentage of over-excavation area when the bucket is excavating; The trench width for slope excavation is S = S2 + a2 × h2 × s; Among them: S2 is the over-excavation area, a2 is the percentage of slope area, h is the depth of slope excavation, and s is the width of slope excavation; The length of excavation in each cycle is L=b×(h+2b×tanθ) / (c×tanθ)-h; Where: b is the width of the bucket frame, h is the exposed depth of the bucket teeth, c is the width of the bucket end face, and θ is the bevel angle, which is 20°.

[0006] In the preferred scheme, in step S3.6, the specific method of double-wheel milling for secondary groove grinding is: control the groove milling machine to sink vertically to the design required elevation, start the motor to cut into the soil layer with teeth, mill the groove hole to the specified depth, adjust the milling wheel position according to the height of the groove bottom to keep the groove bottom consistent, check the diameter and depth after milling, and lift the milling wheel to proceed with the next groove construction after meeting the design requirements.

[0007] In the preferred scheme, in step S3.6, the specific method of hole sweeping by the bored pile driver is as follows: according to the bored pile hole position of the designed elevation, a long spiral drill is used to drill a hole; after the hole is drilled, the bored pile driver is lifted out to check the verticality of the slot hole; buttress construction is performed on the slot section where the verticality deviation exceeds 5‰, and the hole sweeping and clearing of the hole by the bored pile driver is completed.

[0008] In a preferred solution, in step S3.1, the parameters of the prepared mud are controlled to be viscosity 18-23s, colloid rate ≧95%, sand content ≦4%, and mud content ﹤2%.

[0009] In the preferred solution, in step S3, the construction sequence of CSM double-wheel milling is: Use a single-tandem three-wheel milling machine or a double-tandem five-wheel milling machine to construct the slot sections. First, construct the A slot section. After the slag is cleared after the A slot is constructed, construct the B slot. Then, proceed to A, B, C, D, and E in sequence. When the steel cage is found to be pulled out during the construction of the E section, construct BD to the designed elevation to clean the hole. Then use a backhoe to clean the broken pile steel cage and pump water to the designed elevation. Finally, clean the holes of the five sections A, B, C, D, and E that have been constructed in place.

[0010] The CSM double-wheel milling construction method provided by the present invention has the following beneficial effects by adopting the above method: (1) It is suitable for sand layers and silty clay, and can complete the support of deep and large foundation pits and the construction of water cut-off curtains in a relatively short time, which can significantly reduce costs and increase efficiency compared with conventional construction methods; (2) The disturbance to the strata and the surrounding environment during the trenching process is minimal, which effectively solves the constraints of the construction site and allows the corresponding construction to be carried out normally in downtown areas; (3) Construction between piles can avoid the risks of hole collapse and drilling holes that are prone to occur during construction in trenches; (4) The shape of the foundation pit can be controlled by changing the trajectory of the cutter, and the verticality of the groove wall is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 It is a schematic diagram of the construction process of the present invention.

[0011] Figure 2 It is a process flow chart of the present invention.

[0012] Figure 3 It is a schematic diagram of the construction sequence of the present invention. DETAILED DESCRIPTION

[0013] like Figure 1-3 A CSM double-wheel milling construction method comprises the following steps: S1. Measurement and setting out; Place measurement control points along both ends of the project centerline and set up centerline position stakes at both ends. Determine the construction control line on the trench excavation working surface and the double-wheel milling construction surface according to the edge lines in the design drawings; S2, digging trenches; A hydraulic grab bucket is used to dig the trench. After the trench reaches the designed elevation, a mechanical bucket is used to dig the trench. The soil is unloaded using a single bucket digging and reverse loading method. The cross-sectional dimensions of the trench section are measured for self-inspection in each excavation cycle. S3, trenching construction; Wherein, step S3 specifically includes the following steps: S3.1. Use shale to prepare mud, and the mud density is controlled at 1.10-1.25; S3.2. Check whether the slot milling machine and its cutter and milling wheel are operating normally, confirm that the earthwork in the slot section has been excavated, move the slot milling machine to the location, fix the cutting teeth on the cutter with screws, align the axis, start the slot milling machine, align the cutter with the center point of the axis, slowly cut, and start the milling wheel to start excavation; S3.3, inject the mud generated during the excavation process between the cutter and the milling wheel to cool and lubricate the cutter and the milling wheel. The cutter rotates in the soil and cooperates with the milling wheel to squeeze, rub and shear the soil, breaking the soil and discharging it out of the trough together with the mud; S3.4, CSM double wheel milling machine continuously measures the trench width, trench depth, trench depth deviation, and trench axis orientation of the trench section during trench excavation, and compares them with the trenching parameters. If the allowable deviation is exceeded, corrections are made to ensure the trenching quality and meet the design requirements; S3.5. When excavation reaches the designed elevation, stop construction, remove the cutting teeth, and proceed to the next construction section; S3.6. After the trenching is completed, clean the trench wall by using a double-wheel milling machine for secondary trenching or a punching pile driver to sweep the hole and repeat the trenching process.

[0014] In the preferred solution, in step S2, the side wall area S1 when the bucket is excavating and the over-excavation area S2 generated when the bucket is excavating are calculated, and the groove width S of the slope excavation and the length L of each cycle excavation are calculated according to S1 and S2. The specific calculation includes: Side wall area S1 = H × (c × 1.3 + b) × 1 / 2; Where: c is the width of the bucket slot frame, b is the distance between the bucket teeth, and H is the exposed depth of the bucket teeth; Over-excavation area S2 = S1 × (1 + a1); Where: S1 is the excavation side wall area, a1 is the percentage of over-excavation area when the bucket is excavating; The trench width for slope excavation is S = S2 + a2 × h2 × s; Among them: S2 is the over-excavation area, a2 is the percentage of slope area, h is the depth of slope excavation, and s is the width of slope excavation; The length of excavation in each cycle is L=b×(h+2b×tanθ) / (c×tanθ)-h; Where: b is the width of the bucket frame, h is the exposed depth of the bucket teeth, c is the width of the bucket end face, and θ is the bevel angle, which is 20°.

[0015] In the preferred scheme, in step S3.6, the specific method of double-wheel milling for secondary groove grinding is: control the groove milling machine to sink vertically to the design required elevation, start the motor to cut into the soil layer with teeth, mill the groove hole to the specified depth, adjust the milling wheel position according to the height of the groove bottom to keep the groove bottom consistent, check the diameter and depth after milling, and lift the milling wheel to proceed with the next groove construction after meeting the design requirements.

[0016] In the preferred scheme, in step S3.6, the specific method of hole sweeping by the bored pile driver is as follows: according to the bored pile hole position of the designed elevation, a long spiral drill is used to drill a hole; after the hole is drilled, the bored pile driver is lifted out to check the verticality of the slot hole; buttress construction is performed on the slot section where the verticality deviation exceeds 5‰, and the hole sweeping and clearing of the hole by the bored pile driver is completed.

[0017] In a preferred solution, in step S3.1, the parameters of the prepared mud are controlled to be viscosity 18-23s, colloid rate ≧95%, sand content ≦4%, and mud content ﹤2%.

[0018] In the preferred solution, in step S3, the construction sequence of CSM double-wheel milling is: Combination Figure 3 , use a single-tandem three-wheel milling machine or a double-tandem five-wheel milling machine to construct the slot section. First construct the A slot section. After the A slot is constructed and the slag is cleared, the B slot is constructed. Then A, B, C, D, and E are constructed in sequence. When the steel cage is found to be pulled out during the construction of the E section, BD is constructed to the designed elevation to clean the hole, and then a backhoe is used to clean the broken pile steel cage and pump water to the designed elevation. Finally, the holes of the five sections A, B, C, D, and E that have been constructed in place are cleaned. The shaded part in the figure is repeated drilling to ensure the continuity of the wall and the construction quality of the joints. The overlap of the double-wheel milling cement soil mixing wall and the verticality correction of the construction equipment are guaranteed by repeated drilling to achieve the effect of water stopping.

[0019] CSM double-wheel milling machine conducts slotting test milling on site. Before construction, the slag removal efficiency of each slotting machine is calculated based on the test milling results, and the number of slotting machines in the slotting process is determined on site. According to the actual situation on site, the slotting efficiency of each slotting machine must be close to meet the requirement of completing the slotting on time; The slot milling machine is tested 2-3 times before on-site construction. After the test milling, the slag discharge amount, milling soil amount, slot milling machine failure and the working efficiency of each slot milling machine are recorded. The slotting quality of the slots formed under different cutters is determined through trial milling. By analyzing the data after the test milling, the efficiency of the on-site slot milling machinery is reasonably arranged to achieve the requirements of improving construction efficiency and slotting quality.

[0020] Lay out the slots: Use a total station to lay out the center of the slots of each slot milling machine according to the dimensions specified in the drawing, and use white chalk line to draw a circle with a diameter of 2m to position the slot milling machine.

[0021] Drilling and slag removal, place the milling machine drill bit near the center of the slot hole that has been placed, and keep a distance of 20 cm from the adjacent milling machine. The drill bit breaks the stratum. The verticality of the borehole must be controlled during the breaking process. When the design elevation is reached, the drill bit stops working, and the drill rod is automatically extended by controlling the drill bit to automatically pull out and the slag in the hole is automatically discharged. During this process, the slag is automatically discharged to the slag removal device next to the milling machine. Among them, the drill rod is an extendable hollow pile rod that can automatically extend 3 meters. The drill rod automatic extension device is an existing mature technology.

[0022] After the hole is cleaned, the on-site debris is transported to the side of the slot milling machine by crane, and the excess debris is discharged outside the site through a pipe or reused. After the hole is cleaned, the above-mentioned drilling and slag removal construction process is repeated.

[0023] Measure the hole depth and the verticality of the slot. Use the total station to measure the drilling depth and slot depth and monitor the verticality of the slot. If the verticality does not meet the requirements, replace the slot milling machine and re-construction. By measuring the verticality of the slot, if it is found that the verticality of the slot is not good, take corresponding corrective measures to ensure the construction quality.

[0024] Slot hole forming: on the basis of the above-mentioned hole measurement plan, the slot milling machine is used to mill in the hole until the slot hole is formed, and the corresponding cutter construction is adjusted according to the soil requirements of different strata; during the slot forming process, the distance between the two slot milling machines is strictly controlled; during the operation of the slot milling machine, the cutter angle and cutter gap (that is, the inclination angle and position of the cutter teeth) are adjusted in time for different soil layers, so as to achieve the requirements of improving the slotting efficiency and slotting quality.

[0025] During the trenching process, the conditions of the strata should be judged and adjusted. The amount of soil discharged during the construction process is used as an indicator to judge the soil quality of the strata. Different cutters are adjusted according to the soil conditions to speed up the trenching speed.

[0026] During the trenching process, construction must be carried out strictly according to the designed cutter spacing (2.5M). Process parameters such as verticality, cutter spacing, soil discharge volume, trenching time, etc. must be strictly constructed in accordance with the design and technical requirements to meet the construction quality requirements.

[0027] Slot inspection: After the slot is completed, check whether the length, width, and depth of the slot meet the design requirements, whether the verticality and flatness of the slot meet the requirements, and whether there is any residual debris in the slot. Take appropriate measures for the parts that do not meet the design requirements.

[0028] After the slot hole inspection is qualified, the next construction process will be carried out, which is the double-wheel milling of steel cage, steel bar inspection, foundation pit support or water cut-off curtain construction.

[0029] During construction, the distance between the cutters of the double-wheel milling machine is 2.5m. During the grooving process, the distance between the cutters and the control parameters of the construction process are strictly maintained to ensure the construction quality.

[0030] The construction speed can be increased by 5-10 times compared with conventional technology, and large foundation pits can be completed 20-40 days faster.

[0031] The double-wheel milling method can effectively reduce tool wear and damage by adjusting the cutter row and adjusting the milling blade.

[0032] The verticality of the slot forming can be controlled within 1 / 600-1 / 400, and the flatness is less than 20mm.

[0033] The trenching process has little impact on the ground disturbance and surrounding environment, and is suitable for construction in downtown areas and densely populated areas.

[0034] When the terrain conditions are restricted, the collapsed holes and exploration holes in the slots that may affect the construction can be avoided.

[0035] The CSM slot milling machine is used for construction between piles and soil layers, effectively avoiding the risks of hole collapse and drilling holes that may occur during construction inside the slot hole.

[0036] The present invention can adopt an automatic drill rod device (i.e. a hollow extendable drill rod) and a slag pump technology (the slag pump is an existing mature technology, and the automatic extension device is an existing mature technology) during the trenching construction process, effectively reducing the amount of manpower used.

Claims

1. A CSM double-wheel milling construction method, characterized in that The following steps are involved: S1. Measurement and setting out; Place measurement control points along both ends of the project centerline and set up centerline position stakes at both ends. Determine the construction control line on the trench excavation working surface and the double-wheel milling construction surface according to the edge lines in the design drawings; S2, digging trenches; A hydraulic grab bucket is used to dig the trench. After the trench reaches the designed elevation, a mechanical bucket is used to dig the trench. The soil is unloaded using a single bucket digging and reverse loading method. The cross-sectional dimensions of the trench section are measured for self-inspection in each excavation cycle. S3, trenching construction; Wherein, step S3 specifically includes the following steps: S3.

1. Use shale to prepare mud, and the mud density is controlled at 1.10-1.25; S3.

2. Check whether the slot milling machine and its cutter and milling wheel are operating normally, confirm that the earthwork in the slot section has been excavated, move the slot milling machine to the location, fix the cutting teeth on the cutter with screws, align the axis, start the slot milling machine, align the cutter with the center point of the axis, slowly cut, and start the milling wheel to start excavation; S3.3, inject the mud generated during the excavation process between the cutter and the milling wheel to cool and lubricate the cutter and the milling wheel. The cutter rotates in the soil and cooperates with the milling wheel to squeeze, rub and shear the soil, breaking the soil and discharging it out of the trough together with the mud; S3.4, CSM double wheel milling machine continuously measures the trench width, trench depth, trench depth deviation, and trench axis orientation of the trench section during trench excavation, and compares them with the trenching parameters. If the allowable deviation is exceeded, corrections are made to ensure the trenching quality and meet the design requirements; S3.

5. When excavation reaches the designed elevation, stop construction, remove the cutting teeth, and proceed to the next construction section; S3.

6. After the trenching is completed, clean the trench wall by using a double-wheel milling machine for secondary trenching or a punching pile driver to sweep the hole and repeat the trenching process.

2. A CSM double-wheel milling construction method according to claim 1, characterized in that: In step S2, the side wall area S1 when the bucket is excavating and the over-excavation area S2 generated when the bucket is excavating are calculated, and the groove width S of the slope excavation and the length L of each cycle excavation are calculated according to S1 and S2. The specific calculation includes: Side wall area S1 = H × (c × 1.3 + b) × 1 / 2; Where: c is the width of the bucket slot frame, b is the distance between the bucket teeth, and H is the exposed depth of the bucket teeth; Over-excavation area S2 = S1 × (1 + a1); Where: S1 is the excavation side wall area, a1 is the percentage of over-excavation area when the bucket is excavating; The trench width for slope excavation is S = S2 + a2 × h2 × s; Among them: S2 is the over-excavation area, a2 is the percentage of slope area, h is the depth of slope excavation, and s is the width of slope excavation; The length of excavation in each cycle is L=b×(h+2b×tanθ) / (c×tanθ)-h; Where: b is the width of the bucket frame, h is the exposed depth of the bucket teeth, c is the width of the bucket end face, and θ is the bevel angle, which is 20°.

3. A CSM double-wheel milling construction method according to claim 1, characterized in that: In step S3.6, the specific method of double-wheel milling for secondary groove grinding is: control the groove milling machine to sink vertically to the design required elevation, start the motor to cut into the soil layer with teeth, mill the groove hole to the specified depth, adjust the milling wheel position according to the height of the groove bottom to keep the groove bottom consistent, check the diameter and depth after milling, and lift the milling wheel to proceed with the next groove construction after meeting the design requirements.

4. A CSM double-wheel milling construction method according to claim 1, characterized in that: In step S3.6, the specific method of the punching pile driver to sweep the hole is as follows: according to the punching pile hole position of the designed elevation, a long spiral drill is used to drill a hole. After the hole is drilled, the punching pile driver is lifted out to check the verticality of the slot hole. The part of the slot section where the verticality deviation exceeds 5‰ is subjected to buttress construction to complete the punching pile driver to sweep the hole and clean the hole to form the slot.

5. A CSM double-wheel milling construction method according to claim 1, characterized in that: In the step S3.1, the prepared mud parameters are controlled to be viscosity 18-23s, colloid rate ≧95%, sand content ≦4%, and mud content <2%.

6. A CSM double-wheel milling construction method according to claim 1, characterized in that: In step S3, the construction sequence of CSM double-wheel milling is: Use a single-tandem three-wheel milling machine or a double-tandem five-wheel milling machine to construct the slot sections. First, construct the A slot section. After the slag is cleared after the A slot is constructed, construct the B slot. Then, proceed to A, B, C, D, and E in sequence. When the steel cage is found to be pulled out during the construction of the E section, construct BD to the designed elevation to clean the hole. Then use a backhoe to clean the broken pile steel cage and pump water to the designed elevation. Finally, clean the holes of the five sections A, B, C, D, and E that have been constructed in place.

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