CN113774767B - Large-tonnage rolling construction method for filling airport ground - Google Patents

Abstract

The application relates to a large-tonnage rolling construction method for filling a machine site foundation, which belongs to the technical field of foundation construction and comprises the steps of site cleaning, rolling treatment of a base layer by using a large-tonnage roller → paving of earth and stone in a filling area, layering according to filling thickness → at least one static pressure rolling by using the large-tonnage roller → at least four times of vibration rolling by using the large-tonnage roller → compaction settlement measurement → upper-layer filler paving. This application adopts large-tonnage road roller to roll the processing to fill district soil and stone, can obviously reduce the fill number of piles of ground and roll the number of times to shorten the time of rolling, improve and roll the efficiency of construction, and provide a heavy road roller thick-layer paving's construction standard that rolls.

Description

Large-tonnage rolling construction method for filling airport ground

Technical Field

The application relates to the field of foundation construction, in particular to a large-tonnage rolling construction method for filling of a machine yard foundation.

Background

Foundation reclamation is a very important project in airport construction. The airport has large floor area, long runway and higher requirements on the uniformity and settlement change of the foundation. When complex foundations, especially soft foundations are treated, a backfill method is often adopted, earth and stone squares such as stones and the like are backfilled after soft original foundations are dug out, and then forced ramming or rolling treatment is carried out, so that the bearing capacity of the foundations is improved, and the uneven settlement is reduced.

In the foundation filling construction of the engineering such as the airport, the foundation with the filling thickness of more than 30cm is paved and filled layer by layer and is laminated (tamped) and compacted layer by layer at present. For the foundation with larger filling thickness, the maximum loose paving thickness of each layer in the traditional rolling treatment of the airport foundation is not more than 30cm, so that the number of filling layered layers is excessive, the loose paving times and the rolling compaction times are excessive, and the construction progress is slow.

Disclosure of Invention

In order to reduce layering times and compaction times in foundation filling construction and accelerate construction efficiency, the application provides a large-tonnage rolling construction method for foundation filling in a airport ground.

The application provides a large-tonnage rolling construction method for filling of airport ground foundation, which adopts the following technical scheme:

a large-tonnage rolling construction method for filling of an airport ground foundation comprises the following steps:

s100, cleaning a field, leveling the surface of a base layer, removing impurities, and then rolling the base layer by using a large-tonnage roller for at least five times;

s200, paving filler, namely paving earthwork in a filling area, layering according to filling thickness, wherein the paving thickness of each layer is 60-100 cm, and leveling after the first layer is paved;

s300, carrying out static pressure rolling, and carrying out at least one time of static pressure rolling by using a large-tonnage road roller;

s400, performing vibration rolling for at least four times by using a large-tonnage road roller;

s500, compaction settlement measurement;

and S600, repeating S200-S500, and paving the upper-layer filler.

Through adopting above-mentioned technical scheme, utilize large-tonnage road roller to roll ground basic unit and cubic metre of earth and stone packing respectively, the individual layer thickness of paving with the cubic metre of earth and stone improves to 60 ~ 100cm, under the certain circumstances of whole filling thickness, for traditional compaction construction of paving, the number of piles of paving has obviously been reduced, and utilize large-tonnage road roller can reduce the compaction number of times after every layer of paving, when guaranteeing the engineering quality, the construction progress is accelerated, the efficiency of construction has obviously promoted, can shorten the construction cycle of ground filling greatly, can also reduce the oil consumption to a certain extent.

Preferably, in S100, the running speed of the large-tonnage road roller is controlled to be 2-3 km/h, low-frequency vibratory rolling is adopted in the first rolling, and high-frequency vibratory rolling is adopted in the rest rolling.

Through adopting above-mentioned technical scheme, carry out compaction processing to the ground basic unit, avoid taking place great settlement in basic unit when filling the layer soil building stones and rolling, reduce the basic unit and pack the influence that rolls in later stage.

Preferably, in S100, the settlement of the base layer is observed, the average settlement of the whole field is not more than 2mm, and the fluctuation difference of the whole field of the test field is less than 5cm, and the next step is carried out.

By adopting the technical scheme, settlement amount observation is carried out in the grinding process of the base layer, and next paving construction can be carried out after the settlement standard is met, so that the construction quality is guaranteed.

Preferably, in S400, the running speed of the large-tonnage road roller is controlled to be 1.5-2.5 km/h, the vibration frequency is controlled to be 25-30 Hz, and the rolling track overlapping is not less than 1/3.

Through adopting above-mentioned technical scheme, high-frequency vibration rolls the packing layer under the circumstances of driving at low-speed, makes the packing layer by the compaction more fast, rolls the condition that the orbit overlap and is not less than 1/3 also avoids appearing leaking to roll simultaneously.

Preferably, the large-tonnage roller is a 36t roller.

By adopting the technical scheme, the 36t road roller has the characteristics of overweight tonnage and overlarge exciting force, and can rapidly increase the solid volume rate of the foundation filler.

Preferably, in S500, a plurality of observation points are set for each rolling belt, the layer thickness measurement is performed after each rolling, and the difference between the layer thickness value obtained after each rolling pass and the layer thickness value obtained after the last rolling pass is the compaction settlement value.

By adopting the technical scheme, the rolling quality is obtained according to the settlement amount, and the next construction can be guided according to the settlement amount, so that whether the rolling times are increased or not is determined.

Preferably, in S200, the paving thickness is 80cm, and the solid volume ratio of the filling layer is not less than 80% after the static pressure rolling and the vibration rolling are performed for at least five times.

By adopting the technical scheme, the paving thickness of each layer is increased to 80cm, and the minimum rolling pass number of the solid volume rate of the filling layer not less than 80% is determined.

Preferably, in S200, the paving thickness is 80cm, and the solid volume fraction of the filling layer after the one-time hydrostatic rolling and the at least six-time vibratory rolling is not less than 83%.

By adopting the technical scheme, the paving thickness of each layer is increased to 80cm, and the minimum rolling pass number of the solid volume rate of the filling layer not less than 83% is determined.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the thickness of a single filling layer is increased, and the foundation base layer and the filling layer are respectively rolled for multiple times by using a large-tonnage road roller, so that the number of rolling layers and rolling times are reduced, the rolling progress is accelerated, and the construction efficiency is higher;

2. the method provides reasonable guidance for rolling construction of a filling layer with the thickness of 80cm by adopting a 36t large-tonnage road roller, can select a proper rolling scheme according to the solid volume rate requirements of the filling layers of different functional areas, and can be used as the standard for rolling construction of a thicker filling layer of the large-tonnage road roller.

Drawings

Fig. 1 is a flowchart of a large-tonnage rolling construction method for airport foundation filling according to an embodiment of the application.

Detailed Description

The present application is described in further detail below with reference to fig. 1.

Example one

The embodiment of the application discloses a large-tonnage rolling construction method for filling of an airport ground foundation. Selecting an area with a construction area not less than 78m x 65m as a rolling test field, wherein the super width of each of two sides of the rolling test field in the rolling width direction is at least 6m, and the super width of each side of the rolling test field in the rolling direction is at least 6m, so that the vehicle can be staggered and stopped.

Referring to fig. 1, the large-tonnage rolling construction method for airport foundation filling comprises the following steps:

s100, cleaning the field

Before paving the first layer of earth and stone filler, cleaning the test site by using a bulldozer, ensuring the surface of the test site to be smooth, and manually assisting in leveling.

S101, rolling a base layer

After the surface of the test site is leveled, the base layer is rolled by a road roller. In the embodiment, a 36t large-tonnage road roller is adopted to roll the base layer for five times, and the running speed is controlled to be 2.5 km/h. In the rolling process, low-frequency vibration rolling is adopted for the first time, and high-frequency vibration rolling is adopted for the second time to the fifth time. And observing the settlement amount every time in the rolling process until the average settlement amount of the whole field is not more than 2mm and the fluctuation difference of the whole field of the test field is less than 5cm after 2 times of rolling, thereby reducing the influence of the base layer on the rolling test of the filler.

S102, setting elevation control points

After the basic unit is rolled, the elevation of the field is measured, and a plurality of elevation control points are arranged for later-stage filler control.

And (4) checking and accepting the site, and performing the next step after the site is qualified.

S200, first layer of filler

The line was measured and then the placement was done in the test field. The filler is earthwork. The thickness of the first layer of filler is controlled to be 80cm, then the thickness of each layer of filler is fixed to be 80cm, and the thickness of the last layer of filler is determined by the actual thickness when the thickness of the last layer is less than 80 cm. And adopting a forward method and a backward method for paving materials, leveling the surface of the first layer of the filler by using a bulldozer after the paving is finished, and then further leveling by using a digital grader. And (4) performing height measurement after the grader levels to obtain the virtual paving thickness and the relative elevation of the first layer of filler.

10m multiplied by 10m grids are arranged on a test site, each grid is numbered and marked, and a control foundation pile is arranged in a filling area.

S300, static pressure rolling

And after the first layer of filler is leveled, carrying out static pressure rolling once by using a road roller. A36 t large-tonnage road roller is selected as the road roller, and high-range measurement is carried out after static pressure rolling.

S400, vibrating and rolling

Six times of vibration rolling is carried out by adopting a 36t large-tonnage roller. Dividing the rolling range and the strips before rolling, and marking with a lime line to control the vibration rolling range and ensure the rolling quality. The road roller adopts an automatic vibration mode, the driving speed is controlled to be 1.5-2.5 km/h, the vibration frequency is 28Hz, and the rolling tracks are overlapped 1/3. During rolling, the road roller starts to vibrate outside the test site range line 2m, and rolling is performed by adopting a method of forward and backward full vibration in the sequence from the periphery to the middle.

And after the first vibration rolling, performing elevation measurement.

And starting from the third vibration rolling, carrying out compaction degree detection while carrying out high-rise measurement after each rolling is finished. The compaction degree detection is expressed by solid volume rate, and the solid volume rate of each vibration rolling of the first layer is finally obtained by adopting an irrigation method, and the results are shown in table 1.

TABLE 1 data table for detecting solid volume ratio of filler after large tonnage vibration rolling

S500, compaction settlement measurement

The measurement of the thickness of the first layer is carried out after static pressure rolling, and then the measurement is carried out once after rolling, and the measurement is carried out at the same position of the same mesh point every time, thereby ensuring the accuracy of the measurement. And the difference between the first layer thickness value obtained after each time of vibration rolling and the first layer thickness value obtained after the last time of rolling is the compaction settlement value. The measurement accuracy of the settlement is required to be +/-1 mm. In the present embodiment, a plurality of observation points are provided for each rolling belt. And removing abnormal values from the data of a plurality of observation points, and taking the average value as a final compaction settlement value.

S600, and paving of fillers from the second layer to the Mth layer

And selecting whether to pave from the second layer to the Mth layer (M is more than or equal to 2) according to the filling thickness. The second to Mth layers of filler are paved in the same way as the first layer. Firstly, filling, leveling, carrying out static pressure rolling for one time by using a 36t large-tonnage road roller, then carrying out vibration rolling for the first time to the sixth time, and carrying out solid volume rate and compaction settlement measurement after each vibration rolling is finished. The solids volume fraction of the second layer in this example is shown in table 1.

As can be seen from table 1, the first layer had a solid volume fraction of over 80% after the fifth vibratory compaction, and had a solid volume fraction of over 83% after the sixth vibratory compaction; the solid volume rate of the second layer after the fifth vibration rolling is over 80 percent, and the solid volume rate of the second layer after the sixth vibration rolling is over 83 percent.

According to the test results, the solid volume fraction of the filler increased with increasing number of passes. Under the condition that the filling material spreading thickness of a filling area is 80cm, when the required solid volume rate is less than 80%, the vibration rolling times are not less than five times; when the solid volume rate is more than or equal to 83 percent, the vibration rolling times are not less than six times. And under the condition that the solid volume ratio is more than or equal to 80% and less than 83%, the vibration rolling times are not less than five times, and six times of rolling can meet the requirement.

Example two

The embodiment of the application discloses a large-tonnage rolling construction method for filling of an airport ground foundation. Referring to fig. 1, the difference from the first embodiment is that after the first layer of filler is finished, the filler is subjected to air-drying and water-sprinkling treatment. Before the first rolling, the water content of the filler is detected, so that the water content is ensured to be in a proper range. The water content is expressed by the water content. When the water content is low, carrying out water spraying treatment on the filler by using a water spraying truck, then airing the filler, and simultaneously carrying out detection on the water content until the water content meets the requirement, and then carrying out rolling operation; when the water content is higher, the clothes can be directly aired, and if the water on the surface layer is dissipated too fast in the airing process, the clothes can be sprinkled with water for moistening. The moisture content was measured after each pass. The moisture content of the first and second plies after lamination is shown in table 2.

TABLE 2 moisture content detection data table for filler after large-tonnage vibration rolling

The large-tonnage rolling construction method for airport foundation filling is suitable for filling areas with the filling thickness not less than 80cm, and when stone filling is carried out, a 36t large-tonnage road roller is adopted for rolling, so that the number of filling layers and the rolling times can be obviously reduced, the rolling time is shortened, and the rolling efficiency is improved.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (1)

1. A large-tonnage rolling construction method for filling of an airport ground foundation is characterized by comprising the following steps:

s100, cleaning a field, leveling the surface of a base layer by using a bulldozer and removing impurities, then rolling the base layer by using a large-tonnage roller, wherein the rolling frequency is not less than five times, the running speed of the large-tonnage roller is controlled to be 2.5km/h, low-frequency vibratory rolling is adopted for the first rolling, high-frequency vibratory rolling is adopted for the rest rolling, the settlement of the base layer is observed, the average settlement of the whole field is not more than 2mm, and the fluctuation difference of the whole field of the test field is less than 5cm, and carrying out the next step;

after the base course is rolled, measuring the elevation of the field, and setting a plurality of elevation control points for later-stage filling control;

s200, filling and paving, measuring and paying off, paving earth and stone in a filling area, layering the paving materials according to the filling thickness by adopting a filling method and a reversing method, wherein the paving thickness of each layer is 80cm, the actual thickness is determined when the thickness of the last layer is less than 80cm, leveling the surface of the filling material by using a bulldozer after the first layer is paved, and then leveling by using a digital grader;

carrying out high-layer measurement after the first layer is leveled to obtain the virtual pavement thickness and the relative elevation of the first layer of filler, dividing a filling area into grids according to the length of 10m multiplied by 10m, and arranging a control foundation pile in the filling area;

measuring the water content of the filler after each rolling, carrying out air-drying and water-sprinkling treatment on the filler, carrying out water-sprinkling treatment on the filler when the water content is low, and carrying out air-drying treatment on the filler when the water content is high so as to ensure that the water content of the filler is kept within a required range;

s300, carrying out static pressure rolling for at least one time by using a large-tonnage road roller, and carrying out high-range measurement after the static pressure rolling;

s400, performing vibration rolling for at least four times by using a large-tonnage roller, wherein the large-tonnage roller adopts an automatic vibration mode, the driving speed is controlled to be 1.5-2.5 km/h, the vibration frequency is controlled to be 28Hz, and rolling tracks are overlapped 1/3; performing elevation measurement after each vibration rolling by adopting a forward and backward full vibration method in sequence from the periphery to the middle;

detecting the compaction degree, namely detecting the compaction degree after each time of vibration rolling, wherein the compaction degree is represented by a solid volume rate and is detected by an irrigation method, and the solid volume rate of the filling layer after the static pressure rolling for one time and the vibration rolling for at least five times is not less than 80 percent or the solid volume rate of the filling layer after the static pressure rolling for one time and the vibration rolling for at least six times is not less than 83 percent;

s500, compacting settlement measurement, wherein each rolling belt is provided with a plurality of observation points, the layer thickness measurement is carried out after each rolling, the difference between the layer thickness value obtained after each vibration rolling and the layer thickness value obtained after the last rolling is the compacting settlement value, abnormal values of the data of the observation points are removed, and the average value is used as the final compacting settlement value;

s600, repeating S200-S500, and paving the upper-layer filler;

the large-tonnage roller is a 36t roller.

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