Dynamic performance matched filling body parameter detection and compaction quality control method

Abstract

A dynamic performance matched filling body parameter detection and compaction quality control method is a compaction quality control method based on filler density real-time detection in the railway roadbed vibration rolling process and comprises the steps that a compression density barrel is manufactured; the density barrel is filled with roadbed filler, and weighing is carried out; sensors are respectively arranged on the base or the top of the density barrel; calculating the density of the density barrel; calculating the density of the filler in the vibration compaction process; carrying out a heavy hammer compaction test to obtain the maximum dry density of the filler in the vibration compaction process; drying the soil sample by an indoor oven to obtain the water content of the filler; the dynamic compaction coefficient is obtained through the dynamic density rho d and the maximum dry density of the filler; obtaining a time history curve of the dynamic compaction coefficients of different rolling times; the change rule of the compaction state of the filler in the vibratory compaction process is monitored in real time according to the Design Specification of High Speed Railways, and underpressure and overpressure of the vibratory roller are avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of continuous compaction of high-speed railway roadbed. Specifically, the present invention relates to a method for detecting parameters of a filling body and controlling compaction quality with dynamic performance matching. Background Art

[0002] With the increase in the mileage of high-speed railway subgrades in my country, the amount of filling projects for high-speed railway subgrades is bound to increase. At present, how to effectively judge the compaction quality of railway subgrades is an urgent problem that needs to be solved. Therefore, in order to ensure the compaction state of railway subgrades, the control methods currently used at home and abroad are mainly to measure the compaction quality of railway subgrade fillers through methods such as K30, Evd, Ev1, and Ev2. However, these methods all indirectly characterize the compaction quality of fillers through the mechanical properties of fillers. The direct detection method of filler compaction quality is through the sand filling method, which is a destructive detection method and has a long test time. It is not suitable to monitor the density of fillers in real time during vibration compaction.

[0003] Therefore, the present invention makes a self-made longitudinally retractable sedimentation density barrel, and arranges acceleration / displacement sensors on the top and bottom of the density barrel to monitor the relative displacement difference between the top and the bottom of the retractable sedimentation density barrel during vibration compaction, obtains the initial density of the filler according to the mass and volume of the filler, obtains the dynamic density change curve of the filler in the density barrel during vibration compaction, conducts indoor heavy hammer compaction test and measures the moisture content by drying method to obtain the dynamic compaction coefficient, and proposes a vibration compaction rolling process to avoid over-pressure and under-pressure in combination with the requirements of the "High-speed Railway Design Code" on the compaction coefficient of the subgrade surface layer, the subgrade bottom layer and the embankment below the subgrade. Summary of the invention

[0004] The purpose of the present invention is to use a retractable density barrel method combined with a displacement sensor to monitor the time course curve of the density change of the filler in the density barrel during the vibration compaction process in real time, thereby controlling the compaction quality of the railway roadbed. The technical solution is as follows:

[0005] A compressible density barrel comprises a base, a large-diameter cylindrical side portion, and a small-diameter cylindrical side portion, and is characterized in that: the large-diameter cylindrical side portion and the small-diameter cylindrical side portion are filled with roadbed filler, and the inside of the small-diameter cylindrical side portion is filled with roadbed filler; the compressible function of the density barrel is realized by an annular corrugated portion and has lateral constraint and vertical free compression functions.

[0006] A compressible density barrel comprises a base, a large-diameter cylindrical side portion, and a small-diameter cylindrical side portion, and is characterized in that: the inner side portion of the large-diameter cylinder and the outer side portion of the small-diameter cylinder are filled with roadbed filler, and the inner side of the small-diameter cylinder is filled with roadbed filler; the compressibility of the large cylindrical surface and the small cylindrical surface of the density barrel is realized by an annular corrugated portion and has lateral constraint and vertical free compression functions.

[0007] Preferably, the density of the material used for the large and small diameter cylinders is 2.2 g / cm3.

[0008] The present invention also discloses a method for dynamic performance matching fill parameter detection and compaction quality control, which is a compaction quality control method based on real-time detection of filler density during railway roadbed vibration rolling, and comprises the following steps:

[0009] Step 1: according to different filler particle gradations, a compression density barrel with a size suitable for the on-site filling process is manufactured, wherein the compressible density barrel is composed of a base, a large-diameter cylindrical side portion, a small-diameter cylindrical side portion, a roadbed filler is filled between the large-diameter cylindrical side portion and the small-diameter cylindrical side portion, and a roadbed filler is filled inside the small-diameter cylindrical side portion. The compressibility of the density barrel is realized by the annular corrugated portion and has lateral constraints and vertical free compression functions;

[0010] Step 2: Fill the density barrel with roadbed filler, and weigh the total weight M of the filler in the density barrel, the height H1 of the density barrel, the small diameter R1 of the density barrel, and the large diameter R2 of the density barrel;

[0011] Step 3: Arrange acceleration sensors or displacement sensors at the base or top of the density barrel, denoted as A1, A2 and U1, U2.

[0012] Step 4: Calculate the density of the density bucket;

[0013] Step 5: Calculation of filler density during vibration compaction;

[0014] Step 6: Obtain the maximum dry density ρ of the filler during vibration compaction by heavy hammer compaction test dry ;

[0015] Step 7: Dry the soil sample in an indoor oven to obtain the moisture content w% of the filler;

[0016] Step 8: Use the dynamic density ρ d and the maximum dry density of filler ρ dry Get the dynamic compaction coefficient k d =ρ d / (1+w%)ρ dry ;

[0017] Step 9: Repeat the above steps 4-8 to obtain the time history curve of the dynamic compaction coefficient with different rolling times;

[0018] Step 10: According to Section 6.3 and Section 6.4 of the High-Speed ​​Railway Design Code for Embankments below the Subgrade, the compaction standards for the subgrade surface layer, subgrade bottom layer, and embankments below the subgrade are 97%, 95%, and 92%, respectively;

[0019] Step 11: Compare the dynamic compaction coefficient k obtained in step 8 d In accordance with the compaction standards required by the specification in step 9, the changes in the compaction state of the filler during the vibration compaction process are monitored in real time to avoid under- and over-pressure of the vibratory roller.

[0020] Beneficial Effects

[0021] (1) This method is a non-destructive testing method for the compaction coefficient of fillers during vibration compaction;

[0022] (2) This method proposes a control method for the compaction process of different types of fillers, which effectively avoids overpressure and underpressure during vibration compaction;

[0023] (3) This method is a direct detection method for the compaction coefficient of filler during vibration compaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A top view and a front view of the compressible density barrel of the present invention;

[0025] Figure 2 It is a schematic diagram of the acceleration / displacement sensor arrangement method of the present invention;

[0026] Figure 3 It is a schematic diagram of the acceleration time history curve of the top and bottom of the density barrel of the present invention;

[0027] Figure 4 Schematic diagram of the time history curve of the displacement difference between the top and bottom of the density barrel of the present invention, wherein (a) is a schematic diagram of the time history curve of the displacement of the top of the density barrel; (b) is a schematic diagram of the time history curve of the displacement of the bottom of the density barrel; (c) is a schematic diagram of the time history curve of the displacement difference between the top and bottom of the density barrel;

[0028] Figure 5 This is a schematic diagram of the time course curve of the density barrel height change during the first vibration rolling;

[0029] Figure 6 This is a schematic diagram of the time course curve of the density change of the filler in the density barrel during the first vibration rolling;

[0030] Figure 7 This is a schematic diagram of the time course curve of the dry density change of the filler in the density barrel during the first vibration rolling;

[0031] Figure 8 It is the time history curve of the dynamic compaction coefficient of the filling in the density barrel during the first vibration rolling;

[0032] Fig. 9 It is a schematic diagram of the change of the compaction coefficient with the number of rolling times of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with specific embodiments. The given examples are only for illustrating the present invention, but not for limiting the scope of the present invention.

[0034] A method for dynamic performance matching of fill parameters and compaction quality control, comprising the following steps:

[0035] Step (1): According to different filler particle gradations, a compressed density barrel of a size suitable for the on-site filling process is manufactured. The compressible density barrel consists of a base, a large-diameter cylindrical side portion (material density is 2.2 g / cm 3 ), small diameter cylindrical side part (material density is 2.2g / cm 3 ), the side of the large diameter cylinder and the side of the small diameter cylinder are filled with roadbed filler, the inside of the side of the small diameter cylinder is filled with roadbed filler, the compressible function of the density barrel is realized by the annular corrugated part and has lateral constraint and vertical free compression function.

[0036] Step (2): Fill the density barrel with roadbed filler, and weigh the total weight M of the filler in the density barrel, the height H1 of the density barrel, the small diameter R1 of the density barrel, and the large diameter R2 of the density barrel.

[0037] The total weight of the filling in the density barrel M = 100kg, the height of the density barrel H1 = 0.4m, the small diameter of the density barrel R1 = 0.3m, the large diameter of the density barrel R2 = 0.4m,

[0038] Step (3): Refer to the attached Figure 2 , the acceleration sensor or displacement sensor is arranged at the base position of the displacement sensor and the density barrel, and is denoted as A1, A2 and U1, U2 respectively.

[0039] Step (4): There are two ways to calculate the density of the density barrel through step (3): ① Use a data collector to monitor the acceleration time-history curve of the top and bottom of the density barrel and conduct analysis. Perform a quadratic integration on the acceleration time-history curve to obtain the displacement time-history curve during the vibration rolling process. The displacement peak values ​​within 0.5s between the top and bottom of the barrel are used to obtain the relative compression time-history curve between the top and bottom of the density barrel, which is recorded as h1. This method requires a small amount of space and installation, and the volume of the sensor can be ignored to directly calculate the density. ② Use a data collector to monitor the displacement time-history curve of the top and bottom of the density barrel directly. Then, the displacement peak values ​​within 0.5s between the top and bottom of the barrel are used to obtain the relative compression time-history curve between the top and bottom of the density barrel, which is recorded as h1. However, the displacement sensor has a large volume, which affects the volume occupied by the filler of the density barrel. It is necessary to estimate the volume of the displacement sensor through the sand filling method before performing the density calculation. See Attachment Figure 3 .

[0040] Step (5): Calculation method of packing density during vibration compaction:

[0041] See also Figure 4 As shown, (a) by monitoring the acceleration time history curve of the bottom and top of the density barrel during vibration compaction: ① Density barrel height change time history curve H a is the difference between the density bucket height H1 and the relative displacement time history curve h1 between the bottom and top of the density bucket obtained by quadratic integration in the frequency domain. ② The initial density of the filler is ρ c is the packing mass M and the packing volume The ratio of , ③ The dynamic density during vibration is ρ d =ρ c / H1*H a .

[0042] (b) By monitoring the displacement time history curve of the bottom and top of the density barrel during vibration compaction: ① Density barrel height change time history curve H a is the difference between the density barrel height H1 and the relative displacement time history curve h1 between the bottom and top of the density barrel. ② Since the displacement sensor includes the bottom fixed plate and the sensor part, the volume and mass m of the density barrel d It cannot be ignored, so the overall volume of the displacement sensor is first obtained by the sand filling method. The specific calculation steps are as follows: The density of the standard sand is known to be ρ s , put the displacement sensor into an empty bucket V of known volume, pour the standard sand into the empty bucket by free fall until the bucket is full, take out the displacement sensor, and record the remaining standard sand mass in the bucket as m s , then the volume of the sensor V d For Vm s / ρ s ③The initial density of the filler is ρ c is the filler mass (Mm d) and filler volume ④ The dynamic density during vibration is ρ d =ρ c / H1*H a . See attached Figure 5 shown.

[0043] Take the first vibration rolling of the vibratory roller as an example:

[0044] The time-history curve of the height change of the density barrel during the first vibration rolling indicates that the vibration rolling process can cause the barrel wall of the compressible density barrel to undergo longitudinal displacement, so the filler in the barrel is also longitudinally compressed, thereby obtaining the time-history curve of the compression amount of the filler. The time-history curve of the density change of the filler in the density barrel during the first vibration rolling indicates the real-time density change curve of the filler during the rolling process, thereby achieving the purpose of monitoring the filler density during the rolling process.

[0045] Step (6): Conduct an indoor hammer compaction test 96 times with different moisture contents under the same grading curve to obtain the maximum dry density of the filler ρ dry .

[0046] According to engineering experience, the maximum dry density of the filler is 2.3g / cm 3 .

[0047] Step (7): Dry the soil sample in an indoor oven to obtain the moisture content of the filler (w%).

[0048] According to engineering experience, the moisture content of the filler is generally 4%.

[0049] Step (8): Through the dynamic density ρ d and the maximum dry density of filler ρ dry Get the dynamic compaction coefficient k d =ρ d / (1+w%)ρ dry ;

[0050] The time-history curve of dry density change of filler in the density barrel during the first vibration rolling is obtained by combining the moisture content to obtain the time-history curve of dry density change of filler, and then compared with the maximum dry density obtained from the indoor test to obtain the compaction coefficient.

[0051] The time curve of the dynamic compaction coefficient change of the filler in the density barrel during the first vibration rolling is obtained by comparing the dry density change time curve measured on site with the maximum dry density, and is used to judge the compaction quality of the filler.

[0052] Step (9): Repeat the above steps (4)-(8) to obtain the time history curve of the dynamic compaction coefficient for different rolling times.

[0053] The change pattern of compaction coefficient with the number of rolling times is obtained by comparing the dry density results after each rolling. The purpose is to obtain the change pattern of compaction coefficient under different rolling times. If the standard value is reached, the rolling can be stopped in time to achieve the purpose of dynamic monitoring.

[0054] Step (10): According to Section 6.3 and Section 6.4 of the High-Speed ​​Railway Design Code for the embankment below the subgrade, the compaction standards for the subgrade surface layer, subgrade bottom layer and embankment below the subgrade are 97%, 95% and 92% respectively.

[0055] According to the graph showing the change of compaction coefficient with the number of rolling times, the compaction times corresponding to compaction coefficients of 97%, 95% and 92% are 19, 12 and 7 times respectively. The number of vibration rolling times can be accurately obtained to avoid over-pressure and under-pressure.

[0056] Step (11): Compare the dynamic compaction coefficient k obtained in step (8) d In accordance with the compaction standard required by the specification in step (9), the change law of the compaction state of the filler during the vibration compaction process is monitored in real time to avoid under-pressure and over-pressure of the vibratory roller.

[0057] The production method proposed by the present invention is simple to operate, highly feasible, and is an extremely efficient direct detection method for compaction coefficient. The present invention completes the detection of compaction quality during the construction stage and adjusts the construction conditions in areas with poor compaction conditions, avoiding over-pressure and under-pressure, greatly improving the quality inspection efficiency of high-speed railway roadbed construction, and having significant economic and social benefits.

[0058] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A compressible density barrel, comprising a base, a large diameter cylindrical side portion, and a small diameter cylindrical side portion, characterized by: The inner side of the large diameter cylinder and the outer side of the small diameter cylinder are filled with roadbed filler, and the inner side of the small diameter cylinder is filled with roadbed filler; the compressible function of the large cylindrical surface and the small cylindrical surface of the density barrel is realized through the annular corrugated part and has lateral constraint and vertical free compression function.

2. The compressible density barrel according to claim 1, characterized in that: The material density of the large and small diameter cylinders is 2.2 g / cm 3 .

3. A method for dynamic performance matching of fill parameters and compaction quality control, characterized by: Step 1: manufacturing the compressible density barrel of claim 1 with a size suitable for the on-site filling process according to different filler particle gradations; Step 2: Fill the density barrel with roadbed filler, and weigh the total weight M of the filler in the density barrel, the height H1 of the density barrel, the small diameter R1 of the density barrel, and the large diameter R2 of the density barrel; Step 3: Arrange acceleration sensors or displacement sensors at the base or top of the density barrel, denoted as A1, A2 and U1, U2; Step 4: Calculate the density of the density bucket; Step 5: Calculation of filler density during vibration compaction; Step 6: Obtain the maximum dry density ρ of the filler during vibration compaction by heavy hammer compaction test dry ; Step 7: Dry the soil sample in an indoor oven to obtain the moisture content w% of the filler; Step 8: Use the dynamic density ρ d and the maximum dry density of filler ρ dry Get the dynamic compaction coefficient k d =ρ d / (1+w%)ρ dry ; Step 9: Repeat the above steps 4-8 to obtain the time history curve of the dynamic compaction coefficient with different rolling times; Step 10: According to Section 6.3 and Section 6.4 of the High-Speed ​​Railway Design Code for Embankments below the Subgrade, the compaction standards for the subgrade surface layer, subgrade bottom layer, and embankments below the subgrade are 97%, 95%, and 92%, respectively; Step 11: Compare the dynamic compaction coefficient k obtained in step 8 d In accordance with the compaction standards required by the specification in step 9, the changes in the compaction state of the filler during the vibration compaction process are monitored in real time to avoid under- and over-pressure of the vibratory roller.

4. The method for detecting parameters of compacted objects and controlling compaction quality with dynamic performance matching according to claim 3 is characterized by: The compressible density barrel consists of a base, a large-diameter cylindrical side portion, and a small-diameter cylindrical side portion. The space between the large-diameter cylindrical side portion and the small-diameter cylindrical side portion is filled with a roadbed filler, and the interior of the small-diameter cylindrical side portion is filled with a roadbed filler.

5. The method for detecting parameters of compacted objects and controlling compaction quality with dynamic performance matching according to claim 3, characterized in that: There are two ways to calculate the density of a density barrel: ① Use a data collector to monitor the acceleration time-history curves of the top and bottom of the density barrel for analysis, perform quadratic integration on the acceleration time-history curve to obtain the displacement time-history curve during vibration compaction, and obtain the relative compression time-history curve between the top and bottom surfaces of the density barrel by taking the displacement peak values ​​within 0.5s of the top and bottom of the barrel, which is recorded as h1; ② Use a data collector to monitor the displacement time-history curves of the top and bottom of the density barrel directly, and then obtain the relative compression time-history curve between the top and bottom surfaces of the density barrel by taking the displacement peak values ​​within 0.5s of the top and bottom of the barrel, which is recorded as h1.

6. The method for detecting parameters of compacted objects and controlling compaction quality with dynamic performance matching according to claim 5, characterized in that: The method for calculating the density of the filler during vibration compaction includes the following steps: (a) by monitoring the acceleration time history curves of the bottom and top of the density barrel during vibration compaction: ① The time history curve of the height change of the density barrel H a is the difference between the density bucket height H1 and the relative displacement time history curve h1 between the bottom and top of the density bucket obtained by quadratic integration in the frequency domain; ② The initial density of the filler is ρ c is the packing mass M and the packing volume The ratio of , ③ The dynamic density during vibration is ρ d =ρ c / H1*H a ; (b) By monitoring the displacement time history curve of the bottom and top of the density barrel during vibration compaction: ① Density barrel height change time history curve H a is the difference between the density barrel height H1 and the relative displacement time history curve h1 between the bottom and top of the density barrel. ② Since the displacement sensor includes the bottom fixed plate and the sensor part, the volume and mass m of the density barrel d It cannot be ignored, so the overall volume of the displacement sensor is first obtained by the sand filling method. The specific calculation steps are as follows: The density of the standard sand is known to be ρ s , put the displacement sensor into an empty bucket V of known volume, pour the standard sand into the empty bucket by free fall until the bucket is full, take out the displacement sensor, and record the remaining standard sand mass in the bucket as m s , then the volume of the sensor V d For Vm s / ρ s ; ③The initial density of the filler is ρ c is the filler mass Mm d With filler volume ratio; ④ The dynamic density during vibration is ρ d =ρ c / H1*H a .

7. A compaction quality control method based on real-time detection of filler density during railway roadbed vibration rolling, characterized by: The method adopts a dynamic performance matching filling body parameter detection and compaction quality control method as described in any one of claims 3-6.

Images