CN1936270A - Multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure and its construction method - Google Patents

Abstract

The invention relates to a multilayer wall rock grouting stereosphere tunnel bearing structure and constructing method. It has tunnel and the feature is that two layers or over two layers different consolidation holes density, different grouting pressure, different serum species, and different particle of serum would be coated on the wall rock. The invention could be used in water conservancy water and electricity tunneling under the action of super-high pressure cranny groundwater, and could be also used in traffic tunneling and city water supplying tunneling.

Description

A kind of multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure and job practices thereof

Technical field

The present invention relates to a kind of multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure and job practices thereof.Mainly be applicable to water conservancy and hydropower tunnel engineering under the effect of super-pressure water vein, also be applicable to all kinds of traffic tunnel engineerings, urban water supply tunnel engineering simultaneously.

Background technology

Tunnel buried depth related in the engineering construction such as water conservancy and hydropower, traffic is increasing, and the groundwater pressure that runs into often has hundreds of rice even goes up the km head.Because the groundwater recharge scope is big, degradation period is long, handles badly, and the ground water discharge meeting has a negative impact to hydrogeological environment on every side on the one hand, and it is very big difficult and endanger to bring can on the other hand engineering construction and operation, structural safety.

In the hydraulic tunnel design at present, prevent the problem that water body exosmoses in the tunnel often that the designer pays close attention to, measure such as the steel plate liner adopted, concrete and steel plate composite lining, the prestressed reinforced concrete lining cutting, the single consolidation grouting of reinforced concrete lining layer+country rock etc., wherein reinforced concrete lining layer+single country rock consolidation grouting measure is exactly to make full use of the main structure body of country rock as tunnel carrying and antiseepage, adopt single grouting pressure, the tunnel country rock is reinforced in consolidation grouting measures such as single grouting slurries, sealing tunnel periphery rock cranny, improve the globality and the non-deformability of tunnel country rock, strengthen the impervious ability of country rock, it is good that this design more and more becomes the country rock geological conditions, satisfy Norway's criterion, the primary structure measure of tunnel engineering under minimum geostatic stress criterion and the country rock infiltration criterion condition, but this bearing structure is because the grouting of tunnel radial radiation shape cloth hole, along with entering the increase of the country rock degree of depth and make it circumferential distance, progressively strengthens drilled grout hole, under the condition of measures such as identical grouting pressure and grouting slurries, the outer country rock transmission coefficient of general formation is big, the antiseepage bearing structure that the internal layer transmission coefficient is little, mainly use in the tunnel structure that in preventing, blends the carrying internal water pressure outside the water, because the little seepage water pressure that bears of transmission coefficient is big more, so this structure is very unreasonable to bearing high external water pressure, therefore, present all kinds of tunnel structures are not considered the outside underground water external pressure destabilization problems that the free face inverse osmosis is brought in tunnel of tunnel substantially.When tunnel buried depth reaches km even more than 2,000 meter,, will become the principal contradiction of tunnel sealing and structure treatment to the processing of the outer super-pressure water vein prolonged permeation problem of tunnel.

To non-hydraulic tunnels such as traffic engineering, the groundwater pressure that in the past ran into is little, often adopts whole lining cutting or composite lining.In whole lining cutting, concrete lining is main bearing structure; In composite lining, anchor pole pneumatically placed concrete and steel concrete are main bearing structures.When buried depth strengthened, runs into the groundwater effect that surpasses last km head, the pattern of existing with the reinforced concrete lining layer is main body bearing structure just was difficult to adapt to.

Summary of the invention

The objective of the invention is provides a kind of multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure and job practices thereof at the tunnel engineering under buried, the super-pressure water vein effect, with normal operation and the long-term external pressure Stability Analysis of Structures safety that guarantees tunnel.

The technical solution adopted in the present invention is: multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure, have tunnel, it is characterized in that peripheral rock at tunnel is provided with the long-pending consolidation grouting circle of specific grain surface of two layers or more different consolidation grouting hole density and different grouting pressure and different slurries kind and different cement class grouting slurries.

Described outer grouting circle is the most closely knit, the intermediate layer secondly, internal layer grouting circle is the most sparse.

The centre in described intermediate layer grouting circle or its one or two hole of grout hole spaced radial of internal layer grouting circle is provided with the cement mortar sealing of hole of high grade.

The density in described consolidation grouting hole is 1.0 * 1.0m～2.0 * 2.0m.

Described grouting pressure is 1.2～2 times of external water pressures.

Slurries have superfine cement or grinding fine cement or ordinary Portland cement or chemical classes grouting agent, coagulate or polyurethane or epoxy resin as first.

The specific grain surface of described cement class grouting slurries is long-pending to be 3000cm ²/ g～10000cm ²/ g.

A kind of job practices of multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure is characterized in that may further comprise the steps:

1) at first at the consolidation grouting hole of the engine request of tunnel design density array pitch between 1.0 * 1.0m～2.0 * 2.0m, the tunnel peripheral rock is carried out consolidation grouting, by adjusting the position of packer in the grout hole, form closely knit relatively skin grouting circle, the grouting pressure that outer country rock consolidation grouting adopts is 1.5～2 times of external water pressures, the slurries kind adopts superfine cement or grinding fine cement or first to coagulate or polyurethane or epoxy resin, and the specific grain surface of cement plasmoid humor is long-pending to be 6000cm ²/ g～10000cm ²/ g;

2) subsequent position of moving packer to the tunnel center, carry out internal layer two preface consolidation groutings, in this step, strengthen the consolidation grouting hole between array pitch, promptly radially be in the milk in one or two hole, interval, the pressure sealing of hole was directly carried out with high-grade cement mortar in middle hole of not being in the milk before the adjacent holes consolidation grouting, reducing grouting pressure simultaneously is 1.2～1.5 times of external water pressures, the slurries kind adopts the ordinary Portland cement slurries, reduces the long-pending 3000cm of being of specific grain surface of slurries ²/ g～4500cm ²/ g forms radius less than the less consolidation grouting circle of the compactness of outer consolidation grouting circle;

3), increase the number of plies of enclosing-rock cement-grouting circle, operating procedure repeating step 2 by the segments that increases grouting in the grout hole degree of depth and the boring according to the needs of concrete engineering), by that analogy.

The invention has the beneficial effects as follows: this structure makes full use of under the seepage water pressure effect, the permeation fluid mechanics basic principle that structure transmission coefficient and suffered osmotic pressure are inversely proportional to, by rational country rock design of consolidation grouting, realize that the outer country rock consolidation grouting of tunnel circle transmission coefficient is less, the outer water osmotic pressure of should bear mutually is big, internal layer consolidation grouting circle transmission coefficient is bigger, the outer water osmotic pressure of should bear mutually is little, promptly reach tunnel country rock transmission coefficient and successively increase progressively the effect that seepage water pressure successively successively decreases from outside to inside from outside to inside.

Description of drawings

Fig. 1 is the structure chart of 1 two layers of consolidation grouting circle of the embodiment of the invention.

Fig. 2 is the force diagram of the embodiment of the invention 1.

Fig. 3 is the structure chart of 2 three layers of consolidation grouting circle of inventive embodiments.

The specific embodiment

Embodiment 1, as shown in Figure 1 and Figure 2, this example is circular tunnel 1, two layers of country rock consolidation grouting circle, the grouting of each consolidation grouting boring is segmented into two sections.The outer water osmotic pressure that the outer country rock 3 consolidation grouting circles of tunnel are comparatively closely knit, transmission coefficient is little, should bear mutually is big, internal layer country rock 2 consolidation grouting circles are sparse relatively, transmission coefficient greatly, outer water osmotic pressure that should bear mutually is little.Enclose no longer consolidation grouting of its one or two hole of grout hole spaced radial in internal layer grouting, and directly adopt the cement mortar shutoff of high grade to become sealing of hole 6.The density in this routine consolidation grouting hole is about 1.0 * 1.0m, and the grouting pressure that outer country rock consolidation grouting adopts is about 1.5 times of external water pressures, and the slurries kind adopts superfine cement, and the specific grain surface of cement grout is long-pending to be 6000cm ²/ g; The grouting pressure that internal layer country rock consolidation grouting adopts is about 1.2 times of external water pressures, and the slurries kind adopts ordinary Portland cement, and the specific grain surface of cement grout is long-pending to be 3000cm ²/ g.

The job practices of present embodiment may further comprise the steps:

1) at first is about the consolidation grouting hole of array pitch between 1.0 * 1.0m, the tunnel peripheral rock carried out consolidation grouting, by adjusting the position of packer 5 in the grout hole, as packer is arranged in radius r at the engine request of tunnel design density ₂The high pressure consolidation grouting carries out at the place, in order to form closely knit relatively skin grouting circle, so that the underground external water pressure of carrying larger proportion, the grouting pressure that outer country rock consolidation grouting adopts is about 1.5 times of external water pressures, the slurries kind adopts superfine cement, and its specific grain surface is long-pending to be 6000cm ²/ g.After reaching grouting end design standard and closing the slurry sealing of hole, just can form radius is r ₁～r ₂The bigger country rock consolidation grouting circle of the outer compactness of tunnel.

2) the subsequent position of packer 5 of moving to the tunnel center is to radius r ₃The place, carry out internal layer two preface consolidation groutings, in this step, can strengthen the consolidation grouting hole between the array pitch (see figure 1), promptly radially be in the milk in one or two hole, interval, the pressure sealing of hole was directly carried out with high-grade cement mortar in middle hole of not being in the milk before the adjacent holes consolidation grouting, reduce grouting pressure simultaneously and be about 1.2 times of external water pressures, the slurries kind adopts the ordinary Portland cement slurries, reduces the long-pending 3000cm of being of specific grain surface of slurries ²/ g, after reaching grouting end design standard and closing the slurry sealing of hole, just can form radius is r ₂～r ₃The less country rock consolidation grouting circle of tunnel internal layer compactness.

Acting on the external water pressure of two-layer enclosing-rock cement-grouting circle and the hydraulic gradient in somewhere can calculate according to formula 1 and formula 2:

Formula 1:

${\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">H</figure-callout>}}_1=\frac{H_0\&times;\ln \frac{r_2}{{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_3}}{\ln \frac{r_2}{{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_3}+\frac{K_2}{{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">K</figure-callout>}}_1}\&times;\ln \frac{r_1}{{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_2}};$ ${\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">H</figure-callout>}}_2=\frac{{\mathrm{<figure-callout\; id="1"\; label="H"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">H</figure-callout>}}_1\&times;\ln \frac{r_3}{r_0}}{\ln \frac{r_3}{r_0}+\frac{K_0}{{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">K</figure-callout>}}_2}\&times;\ln \frac{r_2}{{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_3}}$

Formula 2: ${\mathrm{<figure-callout\; id="1"\; label="J"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">J</figure-callout>}}_1=2\&times;\frac{(H_1-H_2)}{\ln \frac{r_2}{{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_3}}+2\&times;[\frac{(H_0-H_1)}{\ln \frac{r_1}{r_2}}-2\frac{(H_1-H_2)}{\ln \frac{r_2}{r_3}}]\&times;\frac{r-r_2}{r_1-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_2};$ ${\mathrm{<figure-callout\; id="2"\; label="J"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">J</figure-callout>}}_2=\frac{2\&times;(H_1-H_2)}{\ln \frac{r_2}{{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_3}}\&times;\frac{r-r_3}{r_2-{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="A20061005391700091.png"\; state="\{\{state\}\}">r</figure-callout>}}_3}$

In the formula: J ₁---for skin grouting circle radius is the hydraulic gradient at r place;

J ₂---for internal layer grouting circle radius is the hydraulic gradient at r place;

H _i---for acting on the groundwater pressure at concrete lining and each layer grouting circle edge;

r _i---be the radius of concrete lining and each layer grouting circle;

K _i---be the transmission coefficient of concrete lining and each layer grouting circle.

Can reasonably design each layer grouting circle thickness and transmission coefficient level according to the external water pressure value in tunnel engineering of living in district and the long-term stability infiltration hydraulic gradient of country rock by above-mentioned formula.

Embodiment 2, as shown in Figure 1 and Figure 2, this example also is circular tunnel 1, two layers of consolidation grouting circle.Its basic structure is identical with last example, difference is that the density in this routine consolidation grouting hole is about 2.0 * 2.0m, the grouting pressure that outer country rock 3 consolidation groutings adopt is about 2 times of external water pressures, and the slurries kind adopts grinding fine cement, and the specific grain surface of cement grout is long-pending to be 10000cm ²/ g; The grouting pressure that internal layer country rock 2 consolidation groutings adopt is about 1.5 times of external water pressures, and the slurries kind adopts ordinary Portland cement, and the specific grain surface of cement grout is long-pending to be 4500cm ²/ g.

The job practices of present embodiment may further comprise the steps:

1) at first is about the consolidation grouting hole of array pitch between 2.0 * 2.0m, the tunnel peripheral rock carried out consolidation grouting, by adjusting the position of packer in the grout hole, as packer is arranged in radius r at the engine request of tunnel design density ₂The high pressure consolidation grouting carries out at the place, in order to form closely knit relatively skin grouting circle, so that the underground external water pressure of carrying larger proportion, the grouting pressure that outer country rock consolidation grouting adopts is about 2 times of external water pressures, the slurries kind adopts grinding fine cement, and the specific grain surface of cement plasmoid humor is long-pending to be 10000cm ²/ g.After reaching grouting end design standard and closing the slurry sealing of hole, just can form radius is r ₁～r ₂The bigger country rock consolidation grouting circle of the outer compactness of tunnel.

2) the subsequent position of packer of moving to the tunnel center is to radius r ₃The place, carry out internal layer two preface consolidation groutings, in this step, can strengthen the consolidation grouting hole between the array pitch (see figure 1), promptly radially be in the milk in one or two hole, interval, the pressure sealing of hole was directly carried out with high-grade cement mortar in middle hole of not being in the milk before the adjacent holes consolidation grouting, reduce grouting pressure simultaneously and be about 1.5 times of external water pressures, the slurries kind adopts the ordinary Portland cement slurries, reduces the long-pending 4500cm of being of specific grain surface of slurries ²/ g, after reaching grouting end design standard and closing the slurry sealing of hole, just can form radius is r ₂～r ₃The less country rock consolidation grouting circle of tunnel internal layer compactness.

Embodiment 3, as shown in Figure 3, this example is circular tunnel 1, three layers of country rock consolidation grouting circle.Its basic structure is identical with last example, difference is that this routine country rock consolidation grouting circle is three layers, the grouting segmentation operation of each consolidation grouting boring increases to three sections, the density in consolidation grouting hole is about 1.5 * 1.5m, the grouting pressure that outer country rock 3 consolidation groutings adopt is about 1.8 times of external water pressures, and the slurries kind adopts chemical grouting material epoxy resin; The grouting pressure that country rock 4 consolidation groutings in intermediate layer adopt is about 1.5 times of external water pressures, and the slurries kind is a grinding fine cement, the long-pending 7000cm that is about of its specific grain surface ²/ g; The grouting pressure that internal layer country rock 2 consolidation groutings adopt is about 1.2 times of external water pressures, and the slurries kind adopts ordinary Portland cement, and the specific grain surface of cement grout is long-pending to be 3500cm ²/ g.

The job practices of present embodiment may further comprise the steps:

1) is the consolidation grouting hole of array pitch between 1.5 * 1.5m at first, the tunnel peripheral rock carried out consolidation grouting, by adjusting the position of packer in the grout hole, as packer is arranged in radius r at the engine request of tunnel design density ₂The high pressure consolidation grouting carries out at the place, in order to form closely knit relatively skin grouting circle, so that the underground external water pressure of carrying larger proportion, the grouting pressure that outer country rock consolidation grouting adopts is about 1.8 times of external water pressures, the slurries kind adopts chemical grouting material epoxy resin, after reaching grouting end design standard and closing the slurry sealing of hole, just can form radius is r ₁～r ₂The bigger country rock consolidation grouting circle of the outer compactness of tunnel.

2) the subsequent position of packer of moving to the tunnel center is to radius r ₃The place, carry out intermediate layer two preface consolidation groutings, in this step, can strengthen the consolidation grouting hole between array pitch, promptly radially be in the milk in one or two hole, interval, the pressure sealing of hole was directly carried out with high-grade cement mortar in middle hole of not being in the milk before the adjacent holes consolidation grouting, reduce grouting pressure simultaneously and be about 1.5 times of external water pressures, the slurries kind is a grinding fine cement, the long-pending 7000cm that is about of its specific grain surface ²/ g, after reaching grouting end design standard and closing the slurry sealing of hole, just can form radius is r ₂～r ₃The less relatively country rock consolidation grouting circle of tunnel intermediate layer compactness.

3) move the position of packer to radius r to the tunnel center again ₄The place carries out internal layer three preface consolidation groutings, reduces grouting pressure once more and be about 1.2 times of external water pressures in this step, and the slurries kind adopts the ordinary Portland cement slurries, reduces the long-pending 3500cm of being of specific grain surface of slurries ²/ g, after reaching grouting end design standard and closing the slurry sealing of hole, just can form radius is r ₃～r ₄The country rock consolidation grouting circle of tunnel internal layer compactness minimum.

No matter the grouting agent that the present invention uses is cement class grouting agent (as superfine cement or grinding fine cement or ordinary Portland cement), or chemical classes grouting agent (coagulating or polyurethane or epoxy resin as first) etc., all be the common commodity that can on market, buy.

Claims (8)

1, a kind of multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure, have tunnel, it is characterized in that: the long-pending consolidation grouting circle of specific grain surface that is provided with two layers or more different consolidation grouting hole density and different grouting pressure and different slurries kind and different cement class grouting slurries in the peripheral rock of tunnel.

2, multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure according to claim 1 is characterized in that: described outer grouting circle is the most closely knit, the intermediate layer secondly, internal layer grouting circle is the most sparse.

3, multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure according to claim 2 is characterized in that: the centre in described intermediate layer grouting circle or its one or two hole of grout hole spaced radial of internal layer grouting circle is provided with the cement mortar sealing of hole of high grade.

4, multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure according to claim 1 is characterized in that: the density in described consolidation grouting hole is 1.0 * 1.0m～2.0 * 2.0m.

5, multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure according to claim 1 is characterized in that: described grouting pressure is 1.2～2 times of external water pressures.

6, multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure according to claim 1 is characterized in that: described slurries kind has superfine cement or grinding fine cement or ordinary Portland cement or first to coagulate or polyurethane or epoxy resin.

7, multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure according to claim 1 is characterized in that: the specific grain surface of described cement class grouting slurries is long-pending to be 3000cm ²/ g～10000cm ²/ g.

8, a kind of job practices of multilayer enclosing-rock cement-grouting consolidation ring tunnel bearing structure is characterized in that may further comprise the steps:

1) at first at the consolidation grouting hole of the engine request of tunnel design density array pitch between 1.0 * 1.0m～2.0 * 2.0m, the tunnel peripheral rock is carried out consolidation grouting, by adjusting the position of packer in the grout hole, form closely knit relatively skin grouting circle, the grouting pressure that outer country rock consolidation grouting adopts is 1.5～2 times of external water pressures, the slurries kind adopts superfine cement or grinding fine cement or first to coagulate or polyurethane or epoxy resin, and the specific grain surface of cement plasmoid humor is long-pending to be 6000cm ²/ g～10000cm ²/ g;

2) subsequent position of moving packer to the tunnel center, carry out internal layer two preface consolidation groutings, in this step, strengthen the consolidation grouting hole between array pitch, promptly radially be in the milk in one or two hole, interval, the pressure sealing of hole was directly carried out with high-grade cement mortar in middle hole of not being in the milk before the adjacent holes consolidation grouting, reducing grouting pressure simultaneously is 1.2～1.5 times of external water pressures, the slurries kind adopts the ordinary Portland cement slurries, reduces the long-pending 3000cm of being of specific grain surface of slurries ²/ g～4500cm ²/ g forms radius less than the less consolidation grouting circle of the compactness of outer consolidation grouting circle;

3), increase the number of plies of enclosing-rock cement-grouting circle, operating procedure repeating step 2 by the segments that increases grouting in the grout hole degree of depth and the boring according to the needs of concrete engineering), by that analogy.

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