CN101225744A - Method for laying antifreeze heat-preserving thermal-protective coating of longer road tunnel in freeze-thawing frost-heave area - Google Patents

Abstract

The invention relates to a laying method for an extra-long highway tunnel antifreezing heat preservation and insulation layer in freeze-thaw and frost heave area, which comprises the following steps: A. the determination of the temperature at each place in tunnel: the air temperature value of each point in tunnel is calculated according to the environment temperature in tunnel; B. the determination of the length of the heat preservation and insulation layer: according to the air temperature value at each point in tunnel obtained at A step, the heat preservation and insulation layer is laid at the part where the tunnel inlet-outlet lining annual lowest temperature is lower than zero DEG C, and the length of the heat preservation and insulation layer reaches the part where the tunnel deep lining annual lowest temperature is higher than zero DEG C; the heat preservation and insulation layer is not laid at the part where the tunnel inlet-outlet lining annual lowest temperature is higher than zero DEG C. The laying method for an extra-long highway tunnel antifreezing heat preservation and insulation layer in freeze-thaw and frost heave area has the advantages of less consumption of material, significantly lower laying cost and convenient daily maintenance; therefore, the laying method is particularly suitable for the extra-long highway tunnel antifreezing heat preservation and insulation layer laying in freeze-thaw and frost heave area.

Description

The laying method of the anti-anti-freezing and heat-insulating isolation layer of freeze thawing frost heave area speciality highway tunnel

Technical field

The present invention relates to the laying method of a kind of freeze thawing frost heave area speciality highway tunnel anti-freezing and heat-insulating isolation layer.

Background technology

The regional speciality highway tunnel of seasonal freeze thawing frost heave generally is an over mountain line tunnel, because its length is very long, its EXIT POINT is many, and water yield is big, and property goes out stream throughout the year, and the vertical and horizontal mixing supply of underground water for opening, and causes the lining cutting cracking infiltration in tunnel serious.During season, the infiltration in the lining cutting layer is caught a cold icing at autumn, cold, and the easier swollen distortion even cave in of expanding brings safety problem to the tunnel; Equally, when the spring, when the summer warm season arrives, because icing the dissolving in the lining cutting layer also easily makes the distortion of lining cutting layer.These can cause the serious freeze thawing frost heave disease of lining cutting layer serious, the safety that has seriously hindered tunnel traffic.

Do not freeze for the lining cutting that guarantees the tunnel and to endure cold, the anti-antifreezing measures in tunnel mainly contain heat-supplying method, winter protection door method and lay the heat-barrier material method at present, preceding two kinds owing to have energy consumption or disturb shortcomings such as driving, use less.Laying the heat-barrier material method is a rising in recent years and an advanced heat preservation technology that obtains the great attention of circle, tunnel.The mode of laying heat-barrier material has two kinds: a kind of is to lay heat-barrier material between supporting in the early stage and the secondary lining, is called the heat insulation facture of double-deck lining cutting; Another kind is directly to lay the thermal insulation layer on the secondary lining concrete surface., insulation layer durable from structural safety is convenient to the management and maintenance equal angles, and the surperficial heat insulation facture of directly laying the thermal insulation layer on the lining concrete surface is more reasonable, reliable.

Along with China's development of economic construction, highway construction is advanced by leaps and bounds, and increases at the speciality highway tunnel of building, for this super long tunnel, if also adopt existing system of laying to lay the anti-freezing and heat-insulating layer in whole tunnel internal whole process, its high material consumption, cost height, and regular maintenance inconvenience.

Summary of the invention

Purpose of the present invention just provides the laying method of the anti-anti-freezing and heat-insulating isolation layer of a kind of freeze thawing frost heave area speciality highway tunnel, adopts this method to carry out laying of thermal insulation layer, and its material consumption is little, and laid down cost reduces significantly, and regular maintenance is convenient.

The present invention realizes its goal of the invention, and the technical scheme that is adopted is: the laying method of the anti-anti-freezing and heat-insulating isolation layer of a kind of freeze thawing frost heave area speciality highway tunnel, and its way is:

Determining of temperature everywhere in A, the tunnel: the temperature value that calculates each point in the tunnel according to tunnel environment temperature of living in.

Determining of B, thermal insulation layer length: the temperature value that goes on foot each point in the tunnel that obtains according to A, for the position of import and export lining cutting annual minimum temperature in tunnel less than 0 ℃, then lay the thermal insulation layer, the length of thermal insulation layer reaches the annual minimum temperature of tunnel vertical deep lining cutting and locates greater than 0 ℃; And locate greater than 0 ℃ for the vertical deep lining cutting in tunnel annual minimum temperature, then do not lay the thermal insulation layer.

Compared with prior art, the invention has the beneficial effects as follows:

According to calculating the distribution of determining temperature in the tunnel, the air temperature distribution of speciality highway tunnel is compared with middle short tunnel, following characteristics are arranged: in dead season, advance the increase of the hole degree of depth along the tunnel, temperature in the super long tunnel increases, its temperature of vertical bosom reaches the highest in the tunnel, usually above 0 ℃, the lining cutting in vertical deep, tunnel be can not endure cold in dead season icing.Therefore for super long tunnel, endure cold in the tunnel and the freeze thawing frost heave disease that takes place embodies a concentrated reflection of tunnel import and export section.The inventive method is found out in 1 year tunnel inside lining annual minimum temperature less than 0 ℃ the position and the degree of depth (length) thereof according to calculating, only lays the thermal insulation layer at these positions; And those lining cutting annual minimum temperatures in the middle of the tunnel are higher than 0 ℃ position, then no longer lay.Thereby saved the consumption and the cost of heat insulating material, also reduced the maintenance workload of daily thermal insulation layer simultaneously.

The length of above-mentioned thermal insulation layer is located greater than 0 ℃ at the annual minimum temperature that reaches tunnel vertical deep lining cutting, prolongs 15%-30% to vertical depths, tunnel again.

Owing to lay the interchange of heat that has reduced air and tunnel inwall tunnel the in behind the thermal insulation layer, to compare and do not lay the thermal insulation layer, the degree of depth in the cold air intrusion tunnel is more bigger.For the anti-freezing and heat-insulating that guarantees edge also reaches annual minimum temperature greater than 0 ℃ requirement, on the basis of above-mentioned thermal insulation layer length, prolong the thermal insulation layer length of 15%-30% again to the depths, tunnel, length to the thermal insulation layer is revised, thereby guarantees the effect of the tunnel inward flange anti-freezing and heat-insulating outward of thermal insulation layer.

The temperature value of each point is calculated as follows in the above-mentioned tunnel:

$T\left(h\right)=t_m+A_y\sin \frac{2\mathrm{\π}(d-d_0)}{365}+A_d\sin \frac{2\mathrm{\π}(h-h_0)}{24}$

Wherein, t _mBe the average temperature of the whole year of tunnel environment, A _yBe year variations in temperature amplitude, d ₀, h ₀Be phase place, A _dFor degree/day changes amplitude; t _m, A _y, A _dBe the function of calculation level, obtain with the match mode apart from tunnel portal.

Like this, according to the measurement of temperature everywhere in the historical record of the residing ambient air temperature in tunnel and the tunnel, the method that adopt to return can determine exactly in the tunnel in arbitrarily any in any one hour temperature value, thereby determine to provide foundation for the thermal insulation layer length in the tunnel.

Above-mentioned thermal insulation layer thickness δ determines as follows:

$\frac{1}{2\mathrm{\π}{\mathrm{\λ}}_0}\ln \frac{r_0+{\mathrm{\δ}}_0}{r_0}=\frac{1}{2\mathrm{\π\λ}}\ln \frac{r_0}{r_0-\mathrm{\δ}}$

Wherein: λ ₀Be the coefficient of thermal conductivity of loose rock (soil) body on the face of land, r ₀Be the equivalent radius in tunnel, δ ₀For the maximum in the local meteorological data is frozen deeply; λ is the coefficient of thermal conductivity of selected heat insulating material.

Will lay the position of thermal insulation layer in the tunnel, for guaranteeing this place's lining cutting annual minimum temperature greater than 0 ℃, the Thickness Design of thermal insulation layer is found the solution acquisition by above formula.Thereby can determine the thickness of thermal insulation layer reliably, also not waste heat insulating material simultaneously, further save cost.

Below in conjunction with the specific embodiment the present invention is further specified.

The specific embodiment

Embodiment

A kind of specific embodiment of the present invention is:

The laying method of the anti-anti-freezing and heat-insulating isolation layer of a kind of freeze thawing frost heave area speciality highway tunnel, its way is:

Variations in temperature is definite in A, the tunnel: the temperature value that calculates each point in the tunnel according to tunnel environment temperature of living in;

Determining of B, thermal insulation layer length: the temperature value that goes on foot each point in the tunnel that obtains according to A, for the position of import and export lining cutting annual minimum temperature in tunnel less than 0 ℃, then lay the thermal insulation layer, the length of thermal insulation layer reaches the annual minimum temperature of tunnel vertical deep lining cutting and locates greater than 0 ℃; And locate greater than 0 ℃ for the vertical deep lining cutting in tunnel annual minimum temperature, then do not lay the thermal insulation layer.

The length of thermal insulation layer is located greater than 0 ℃ at the annual minimum temperature that reaches tunnel vertical deep lining cutting, prolongs 15%-30% to vertical depths, tunnel again.

According to meteorology knowledge, its annual change and the diurnal variation of temperature are SIN function, and then, the measured data according to the temperature of each point in local meteorological record and the tunnel can draw following formula, thereby try to achieve any a bit any one hour temperature value in the tunnel:

$T\left(h\right)=t_m+A_y\sin \frac{2\mathrm{\π}(d-d_0)}{365}+A_d\sin \frac{2\mathrm{\π}(h-h_0)}{24}$

Wherein, t _mBe the average temperature of the whole year of tunnel environment, A _yBe year variations in temperature amplitude, d ₀, h ₀Be phase place, A _dFor degree/day changes amplitude; t _m, A _y, A _dBe the function of calculation level, obtain with the match mode apart from tunnel portal.

In the inventive method each point year lowest temperature value be the minimum value that above-mentioned formula calculates respective points.

Thermal insulation layer thickness δ determines as follows:

$\frac{1}{2\mathrm{\π}{\mathrm{\λ}}_0}\ln \frac{r_0+{\mathrm{\δ}}_0}{r_0}=\frac{1}{2\mathrm{\π\λ}}\ln \frac{r_0}{r_0-\mathrm{\δ}}$

Wherein: λ ₀Be the coefficient of thermal conductivity of loose rock (soil) body on the face of land, r ₀Be the equivalent radius in tunnel, δ ₀For the maximum in the meteorological data is frozen deeply; λ is the coefficient of thermal conductivity of selected heat insulating material.

The maximum on top layer, base area of the present invention is frozen the thickness that designs frostproof course deeply, makes the present invention can guarantee that freeze thawing frost heave disease does not take place in the tunnel.

The present invention is when implementing, and the selection of tunnel insulation heat-barrier material is selected heat preserving and insulating material in line with economical, safety, principle effective and that be convenient to keep in repair.Carry out preferably from parameters such as coefficient of thermal conductivity, temperature stability, serviceability temperature scope, combustibility, density, water absorption rates.

The super long tunnel of indication of the present invention is meant that length is greater than the 3km tunnel.

Claims (4)

1. the laying method of the anti-anti-freezing and heat-insulating isolation layer of freeze thawing frost heave area speciality highway tunnel, its way is:

Determining of temperature everywhere in A, the tunnel: the temperature value that calculates each point in the tunnel according to tunnel environment temperature of living in;

Determining of B, thermal insulation layer length: the temperature value that goes on foot each point in the tunnel that obtains according to A, for the position of import and export lining cutting annual minimum temperature in tunnel less than 0 ℃, then lay the thermal insulation layer, the length of thermal insulation layer reaches the annual minimum temperature of tunnel vertical deep lining cutting and locates greater than 0 ℃; And locate greater than 0 ℃ for the vertical deep lining cutting in tunnel annual minimum temperature, then do not lay the thermal insulation layer.

2. the laying method of the anti-anti-freezing and heat-insulating isolation layer of a kind of freeze thawing frost heave area speciality highway tunnel according to claim 1, it is characterized in that: the length of described thermal insulation layer is located greater than 0 ℃ at the annual minimum temperature that reaches tunnel vertical deep lining cutting, prolongs 15%-30% to the depths, tunnel again.

3. the laying method of the anti-anti-freezing and heat-insulating isolation layer of a kind of freeze thawing frost heave area speciality highway tunnel according to claim 1 is characterized in that: the temperature value of each point is calculated as follows in the described A step tunnel:

$T\left(h\right)=t_m+A_y\sin \frac{2\mathrm{\π}(d-d_0)}{365}+A_d\sin \frac{2\mathrm{\π}(h-h_0)}{24}$

Wherein, t _mBe the average temperature of the whole year of tunnel environment, A _yBe year variations in temperature amplitude, d ₀, h ₀Be phase place, A _dFor degree/day changes amplitude; t _m, A _y, A _dBe the function of calculation level, obtain with the match mode apart from tunnel portal.

4. the laying method of the anti-anti-freezing and heat-insulating isolation layer of a kind of freeze thawing frost heave area speciality highway tunnel according to claim 1, it is characterized in that: described thermal insulation layer thickness δ determines as follows:

$\frac{1}{2\mathrm{\π}{\mathrm{\λ}}_0}\ln \frac{r_0+{\mathrm{\δ}}_0}{r_0}=\frac{1}{2\mathrm{\π\λ}}\ln \frac{r_0}{r_0-\mathrm{\δ}}$

Wherein: λ ₀Be the coefficient of thermal conductivity of loose rock (soil) body on the face of land, r ₀Be the equivalent radius in tunnel, δ ₀For the maximum in the meteorological data is frozen deeply; λ is the coefficient of thermal conductivity of selected heat insulating material.