JP2015078597A - Antifreeze structure of road surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antifreeze structure of a road surface which can prevent freezing of a paved road surface in a tunnel etc. by utilizing geothermal energy.SOLUTION: In a pavement part of a tunnel etc., an opening area part of a base course and a road bed using sediment and ballast is filled with gelatinous liquid. Silica rock is used for the ballast of the base course, and the pavement surface of the pavement part is formed by an upper surface of a concrete panel using the silica rock as aggregate. Through filling of the opening area part with the gelatinous liquid, heat transfer of the geothermal energy from the layer of the base course and the road bed to the pavement surface can be promoted.

Description

  The present invention relates to a road surface freezing prevention structure for preventing freezing of a road surface, for example, on a paved road in a winter tunnel.

On a tunnel road surface in a cold region, water and spring water drawn by the tires of passing vehicles may freeze due to a decrease in temperature. As a countermeasure, antifreeze spraying is often used.
The main component of many antifreeze agents is a chlorinated compound such as sodium chloride or calcium chloride, which adversely affects concrete and steel materials in the tunnel, as well as disaster prevention equipment and electrical wiring.

  In some cases, a sprinkling snow melting method is used. In the water sprinkling snow melting method, water supply pipes are installed on the road, and ground water or hot water is sprayed from the water sprinkling nozzles onto the road surface to melt the snow. there's a possibility that. If groundwater is used, it may cause land subsidence.

  The heat-snow melting method is to install hot water pipes, electric heaters, etc. inside the road surface, and to prevent freezing of the road surface and snow melting by the heat supplied from this, but the equipment and the energy cost for operating it are low. high.

There is also a method of preventing freezing of the road surface using geothermal heat. This connects the heat collecting pipe buried in the wall surface or underground of the tunnel mine and the heat radiating pipe buried in the tunnel pit, and circulates the geothermal heat with water. However, this also increases the installation cost, and an additional amount of 60 to 120,000 yen per unit freezing prevention area (m ² ) is required.

JP-A-8-53807

  The present invention has been made in view of such circumstances, for example. The purpose of the present invention is to promote heat transfer of the pavement and the roadbed / basement layer, and effectively use the heat held by the ground such as the tunnel ground. Another object of the present invention is to provide a road surface anti-freezing structure that efficiently prevents freezing of a road surface such as a road surface in a tunnel at low cost.

In order to solve the above problems, the present invention employs the following means.
That is, the anti-freezing structure for a road surface according to the present invention is characterized in that in a paved road, a liquid is filled in a gap portion of a roadbed and roadbed using earth and sand or crushed stone.

  In the anti-freezing structure on the road surface, the liquid to be filled can be made into a gel.

  Further, in the above road surface anti-freezing structure, soot can be mixed with the liquid to be filled.

  In the anti-freezing structure for each road surface, sodium silicate can be mixed with the liquid to be filled.

  In the anti-freezing structure for each road surface, silica stone can be used for crushed stone of the roadbed.

  And in the anti-freezing structure of each said road surface, it can be set as a pavement surface by the concrete panel which used the silica stone as an aggregate.

  According to the first aspect of the present invention, the geothermal heat contained in the ground passes through the concrete wall covering the tunnel, and reaches the road surface through the road bed and roadbed. At that time, the heat transfer efficiency is higher when the gap of the roadbed and roadbed (thermal conductivity of air 0.024 w / m · k) is filled with liquid such as water (thermal conductivity 0.63 w / m · k). The road surface can be prevented from freezing.

  According to the experiment (University of Fukui / Tera ▲ Saki / Hiraki / August 2013), dry soil (50% on-site soil + 50% silica and 50% silica sand) has a thermal conductivity of 0.47 w / m · k. The thermal conductivity (mass moisture content 5 to 10%) was 1.0 to 1.7 w / m · k.

  According to claim 2 of the present invention, since the filled liquid is in a gel form, the liquid does not flow out and remains in the gap of the roadbed or the roadbed.

  And according to Claim 3 and Claim 4 of this invention, it becomes a stable gel form by mixing a powder or sodium silicate with a liquid, and it remains in the space | gap of a roadbed or a roadbed.

  According to the experiment (University of Fukui / Tera ▲ Saki / Hiraki / August 2013), the thermal conductivity of wet soil (45% on-site soil + 45% silica and quartz sand + 10% mineral water) mixed with straw powder is 2.0 w / m · k, which is higher than dry soil and wet soil with only water as described in paragraph 0015.

  According to claim 5 of the present invention, silica stone having a high thermal conductivity (thermal conductivity 5.0 w / m · k) is used for crushed stone (usually thermal conductivity 0.9 w / m · k of crushed stone). As a result, the heat conduction between the ground covering the tunnel and the road surface is improved, and freezing prevention can be effectively achieved.

  Furthermore, according to claim 6 of the present invention, by using a concrete panel made of silica stone aggregate on the pavement surface, not only the heat conduction between the ground and the road surface is further improved, but also the construction period is reduced. Shortened.

Sectional drawing which looked at one embodiment of the freezing prevention structure of the road surface concerning this invention from the front side

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
FIG. 1 shows a case where the present invention is applied to a tunnel, and shows an embodiment of a structure for preventing freezing of a road surface in the tunnel. The present invention includes a tunnel ground 1, invert concrete 2, covering concrete 3, roadbed 4, roadbed 5, pavement portion of concrete panel 6, road surface 7, crushed stone 8, and aggregate 9.
Hereinafter, this operation will be described in order in FIG.

  In FIG. 1, when the temperature effect of the tunnel ground 1 is ignored, in the severe winter season, the road surface 7 has water or spring water drawn by the tires of the passing vehicle due to a temperature drop due to ventilation air in the tunnel, May freeze below 0 ° C.

  However, even in the severe winter season, the temperature in the tunnel ground 1 is kept at 10 ° C to 15 ° C. The heat reaches the pavement surface including the concrete panel 6 through the covering concrete 3, the inverted concrete 2, the road floor 4, and the roadbed 5, and raises the temperature of the road surface 7.

In this case, the temperature of the road surface 7 depends on the amount of heat up to the road surface 7. That is, if the amount of heat from the tunnel ground 1 to the road surface 7 with respect to the cooling effect from the tunnel environment on the road surface 7 is small, the road surface 7 is frozen.
Moreover, if there is much heat amount from the tunnel ground 1 to the road surface 7 with respect to the cooling effect | action from the tunnel environment to the road surface 7, the road surface 7 will not freeze.

  The amount of heat that affects the freezing of the road surface 7 is greatly affected by the heat transfer efficiency from the invert concrete 2, the road floor 4, and the roadbed 5 to the concrete panel 6.

  In general, the road bed 4 and the road bed 5 have gaps, which is a factor that hinders heat transfer. However, by filling the gap with a liquid, for example, water, the gap disappears, the heat transfer efficiency of the portion increases, and a large amount of heat moves to the road surface.

  However, if it is a highly fluid liquid such as water, it will flow out without being retained in the gap. Therefore, the liquid is cured in a gel form to prevent outflow.

  As a method for maintaining the liquid in a gel state, water is mixed with starch or sodium silicate and filled.

  As a filling method, there are a method in which a liquid in which water powder or sodium silicate is mixed with water is mixed with the crushed stone 8 and a filling method in which the liquid is injected into the road bed 4 and the road bed 5 from the injection needle at regular intervals.

  If ordinary crushed stone 8 used for the road bed 4 and the road bed 5 is replaced with silica stone and silica sand having high thermal conductivity, the heat transfer efficiency of the portion is increased, and a large amount of heat moves to the road surface 7.

  By using silica stone with high thermal conductivity for the aggregate 9 of the concrete panel 6, the heat transfer efficiency of this portion is increased, and a large amount of heat moves to the road surface. In that case, the filling water is also injected into the gap between the pavement of the concrete panel 6 and the roadbed 5.

  INDUSTRIAL APPLICABILITY The present invention is used as a road structure for preventing road surface freezing in, for example, a paved road in a winter tunnel, a general paved road, a pavement part such as a parking lot, and a pavement part of a sidewalk.

DESCRIPTION OF SYMBOLS 1 Tunnel ground 2 Invert concrete 3 Covered concrete 4 Road floor 5 Roadbed 6 Concrete panel 7 Road surface 8 Crushed stone 9 Aggregate

Claims (6)

  In the pavement, a road surface freezing prevention structure characterized by filling a gap in a roadbed and roadbed using earth and sand or crushed stone.   2. The road surface anti-freezing structure according to claim 1, wherein the liquid to be filled is in a gel form.   2. The road surface anti-freezing structure according to claim 1, wherein the liquid to be filled is mixed with soot powder.   2. A road surface anti-freezing structure according to claim 1, wherein sodium silicate is mixed with the liquid to be filled.   The road surface freezing prevention structure according to any one of claims 1, 2, 3, and 4, characterized in that silica stone is used for the crushed stone of the roadbed.   The road surface freezing prevention structure according to any one of claims 1, 2, 3, 4, and 5, wherein the pavement surface is formed by a concrete panel made of silica stone as an aggregate.

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