CN111894033A - A construction method of pipe gallery with first curing and then excavation - Google Patents

Abstract

The invention discloses a construction method of a pipe gallery which is solidified and excavated, in particular to a construction method of a pipe gallery which does not need supporting excavation in a soft soil area, and the construction method mainly comprises the following steps: curing agent ratio design, field treatment, in-situ curing treatment, pipe gallery excavation, pipe gallery construction and solidified soil backfilling. The method is used for solidifying the soft soil body in the pipe gallery excavation range to form solidified soil with certain self-supporting capacity, the pipe gallery is excavated in the solidified soil, the soil bodies on two sides can resist soil pressure generated by excavation, and engineering safety can be guaranteed. The excavated soil body can be used as backfill on the upper part of the pipe gallery after resource utilization, and can also provide high-quality fillers for other road projects. The method can avoid driving of the support piles, resource utilization of the waste soil body is achieved, economic benefits are higher, and environmental protection is facilitated.

Description

A construction method of pipe gallery with first curing and then excavation

technical field

The invention belongs to the technical field of urban underground pipeline layout and maintenance, and in particular relates to a pipe gallery construction method of first curing and then excavating.

Background technique

The pipe gallery is used to place pipelines. The integrated pipe gallery integrates various pipelines such as electricity, telecommunications, gas, water supply, and heat, and has the advantages of comprehensiveness, long-term efficiency, maintainability, earthquake resistance and disaster prevention, environmental protection, and low cost. It is an important urban municipal infrastructure project with the characteristics of cost, investment diversity and operational reliability. Today, with the acceleration of urbanization and the increase in the demand for various pipelines, the distribution range of pipe corridors in cities is gradually increasing, and sometimes it is inevitable to excavate pipe corridors on soft soil foundations.

Due to the limitation of the construction site, the excavation of urban pipe gallery is mostly in the form of excavation with support. The traditional pipe gallery construction needs to drive cast-in-place piles and steel sheet piles on both sides of the construction area for peripheral support, and then excavate. This requires consideration of the entry of large construction equipment, urban height restrictions, and support costs. . Excavation of pipe gallery in soft soil area produces a large amount of waste soil. These waste soils are often difficult to handle due to their high water content, high viscosity, poor drainage, low strength, and large void ratio. During transportation of soft soil, special attention should be paid to transport vehicles. It will cause land occupation and environmental damage when stacking. On the other hand, the backfill after the completion of the pipe gallery requires high-quality fillers, and the production of conventional fillers such as slag requires additional quarrying. In the current environmental protection strategy, the resource utilization of waste soil is proposed, and how to use the soil rationally is the main focus.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a pipe gallery construction method with simple construction method, resource utilization of waste soil, environmental protection and higher economic benefits.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme: a construction method of a pipe gallery for excavation after curing, comprising the following steps:

Step 1, design calculation: including curing agent ratio determination and curing area design;

Step 1a, determination of the ratio of the curing agent: determine the ratio of the curing agent through an indoor test;

Step 1b, curing area design: design and calculate the in-situ curing construction area;

Step 2, site treatment: including cleaning the site and assembling equipment into the site;

Step 2a, site preparation: mainly includes the drainage of the site surface of the in-situ curing construction area and the cleaning of surface stones and other debris;

Step 2b, the assembly equipment enters the site: the power supply system, the feeding system and the stirring equipment are assembled and then enter the in-situ curing construction area site in step 2a;

Step 3, in-situ solidification treatment: perform in-situ solidification treatment on the soft soil of the in-situ solidification construction site in step 2b, and the in-situ solidification treatment is to use in-situ solidification equipment to stir and mix the soft soil and the solidifying agent to achieve solidification;

Step 4, excavation of the pipe gallery: After the strength of the solidified soil after curing in step 3 meets the requirements, use an ordinary excavator to enter the site to excavate the pipe gallery, and retain the excavated solidified soil;

Step 5, construction of pipe gallery: enter the construction of the pipe gallery after excavation in step 4;

Step 6, backfill with solidified soil: After the construction of the pipe gallery is completed, backfill with the solidified soil retained in Step 4.

Further, the in-situ curing construction area in step 1b is trapezoidal or stepped. According to different curing agent ratios and site conditions, the curing area needs to be specifically designed, which can be trapezoidal or stepped. The design parameters include B1, H, H1 and slope foot α in Figure 1.

Further, B ₁ > 50 cm, 150 cm > H ₁ > 50 cm satisfies the functions of water passage or power supply of the pipe gallery.

Further, it is characterized in that the solidifying agent in step 3 includes powder or slurry, the water content of soft soil in step 3 is 30% to 100%, and the mass content of the solidifying agent is 6% to 6% of the original soil. 20%.

Further, the curing agent is a conventional curing agent, which is commercially available.

Further, the in-situ curing treatment in step 3 may be directly cured in situ on the cleaned site.

Further, in the step 3, the solidification method is to use in-situ solidification equipment to mechanically stir and solidify the silt vertically up and down, or use layered stirring to solidify the sludge, and the solidification treatment depth must at least reach a high-quality soil layer.

Further, the solidified soil excavated on the side after the excavation of the pipe gallery in step 4 can be used as a permanent stress-bearing structure to avoid redundant support, and can be excavated directly by ordinary excavators.

Further, the in-situ curing stirring equipment may include stirring arms, mixing rollers, blade mechanisms, curing agent feeding pipes, spraying devices, and the like. The two sides of the bottom of the stirring arm have two inclined surfaces inclined inward, and at least one mixing roller is respectively provided on each inclined surface. The mixing roller is driven to rotate by the driving device, and the mixing roller is in the shape of a truncated cone; the mixing roller A blade mechanism is distributed on the upper part; a retractable curing agent feeding pipe is installed inside the stirring arm. A spray device is provided at the end of the curing agent feeding pipe.

The present invention has the following positive effects:

(1) In the present invention, before the excavation of the pipe gallery, the soft soil and the curing agent are stirred, mixed and cured by using a stirring device, and the curing speed is fast and the efficiency is high.

(2) The present invention avoids the construction of supporting piles in the excavation construction of the pipe gallery, and has the advantages of simple operation and high economic benefit.

(3) The present invention realizes the reuse of waste soil after excavation, saves resources and is beneficial to environmental protection.

Description of drawings

Figure 1 is the construction flow chart of the pipe gallery that is first cured and then excavated;

Figure 2 is a schematic diagram of the construction of the pipe gallery excavated after curing;

Figure 3 is a cross-sectional view of the curing area;

FIG. 4 is a schematic diagram of the in-situ curing equipment.

Among them, B ₁ is the width of the top surface, H is the height of the bottom from the top surface, H ₁ is the height of the bottom from the bottom of the pipe gallery area, and α is the toe of the slope.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These drawings are all simplified schematic diagrams, and only illustrate the basic structure of the present invention in a schematic manner, so they only show the structures related to the present invention.

Example 1

Referring to Fig. 1, the construction method of the pipe gallery of the present invention for first curing and then excavation includes the following steps: determining the proportion of curing agent, designing and calculating the curing area, cleaning the site, entering the assembly equipment, in-situ curing treatment, and excavating the pipe gallery. , Pipe gallery construction, backfilling with solidified soil. The specific expansion is as follows:

Step 1, design calculation: including the determination of the curing agent ratio and the design of the curing area.

Step 1a, determination of the ratio of the curing agent: determine the ratio of the curing agent through an indoor test.

Step 1b, curing area design: design and calculate the in-situ curing construction area.

Specifically, the soil was taken back to the laboratory for strength tests, and different dosages of curing agents were added according to the properties of the soil. Generally, the soil sample is made into a cylindrical sample with a diameter of 39.1mm and a height of 80mm, and an unconfined compressive strength test is carried out to check whether it meets the design or use requirements. The unconfined compressive strength test can convert the bearing capacity of the soil and is one of the main test methods for the mix ratio of solidified soil.

Wherein, the curing area described in this application needs to be designed according to the mixing ratio of different curing agents. The curing area can be trapezoidal or stepped, and the design parameters include B ₁ , H , H ₁ and slope foot α. A certain thickness is reserved at the lower part of the pipe gallery to ensure that the bearing capacity of the foundation can meet the requirements.

Each parameter index satisfies the following conditions: B ₁ > 50 cm, 150 cm > H ₁ > 50 cm to meet the functions of water passage or power supply of the pipe gallery.

Step 2, site treatment: including cleaning the site and assembling equipment to enter the site.

Step 2a, site preparation: mainly includes the drainage of the site surface of the in-situ curing construction area and the cleaning of surface stones and other debris;

Step 2b, the assembly equipment enters the site: the power supply system, the feeding system and the stirring equipment are assembled and then enter the site of the in-situ curing construction area in step 2a.

Step 3, in-situ curing. Perform in-situ solidification according to the soil solidification area determined in the preceding steps. In-situ solidification can use strong stirring in-situ solidification or conventional soil mixing construction methods, and the solidifying agent is uniformly mixed with the soil through a stirring device to achieve the purpose of soil reinforcement.

Specifically, when the in-situ solidification equipment is used to solidify the soft soil, the selected solidifying agent is powder or slurry, which is selected according to the water content of the soft soil and environmental requirements. The curing agent is mixed with soft soil for rapid curing.

In this example, a conventional concrete sealing and curing agent is used, which is commercially available.

Referring to FIG. 4 , the in-situ curing equipment described in this application includes a power supply system, a material supply system, and a stirring device, and an external power supply or self-generated power can be selected according to on-site conditions.

Specifically, the in-situ curing and stirring equipment includes a stirring arm, a mixing roller, a blade mechanism, a curing agent feeding pipe, a spray device, and the like. The two sides of the bottom of the stirring arm have two inclined surfaces inclined inward, and at least one mixing roller is respectively provided on each inclined surface. The mixing roller is driven to rotate by the driving device, and the mixing roller is in the shape of a truncated cone; the mixing roller A blade mechanism is distributed on the upper part; a retractable curing agent feeding pipe is installed inside the stirring arm. A spray device is provided at the end of the curing agent feeding pipe.

Specifically, the solidification method is to use in-situ solidification equipment to mechanically stir and solidify the silt vertically up and down, or use layered stirring to solidify the sludge, and the solidification treatment depth must at least reach a high-quality soil layer.

Step 4, pipe gallery excavation. After the strength of the solidified soil area meets the corresponding bearing capacity requirements, ordinary excavators can be used to approach the site and excavate in the pipe gallery area. Because the soil around the pipe gallery has a certain strength, it can resist the earth pressure caused by the excavation of the pipe gallery and maintain the stability of the soil in the solidified area. This method can reduce the setting of internal supports and provide enough space for the construction of the pipe gallery.

Step 5, pipe gallery construction. After the pipe gallery area is excavated, the construction of the pipe gallery can be carried out, and the pipe gallery can be poured or spliced to form the pipe gallery.

Step 6, backfill with solidified soil. When the construction of the pipe gallery is completed, the backfill materials on the side of the pipe gallery and the top of the pipe gallery can be filled with excavated soil materials, or the solidified soil can be transported and reused to realize the resource utilization of waste soil.

Claims (5)

1. a pipe gallery construction method for excavation after first curing, is characterized in that, comprises the following steps: Step 1, design calculation: including curing agent ratio determination and curing area design; Step 1a, determination of the ratio of the curing agent: determine the ratio of the curing agent through an indoor test; Step 1b, curing area design: design and calculate the in-situ curing construction area; Step 2, site treatment: including cleaning the site and assembling equipment into the site; Step 2a, site preparation: mainly includes the drainage of the site surface of the in-situ curing construction area and the cleaning of surface stones and other debris; Step 2b, the assembly equipment enters the site: the power supply system, the feeding system and the stirring equipment are assembled and then enter the in-situ curing construction area site in step 2a; Step 3, in-situ solidification treatment: perform in-situ solidification treatment on the soft soil of the in-situ solidification construction site in step 2b, and the in-situ solidification treatment is to use in-situ solidification equipment to stir and mix the soft soil and the solidifying agent to achieve solidification; Step 4, excavation of the pipe gallery: After the strength of the solidified soil after curing in step 3 meets the requirements, use an ordinary excavator to enter the site to excavate the pipe gallery, and retain the excavated solidified soil; Step 5, construction of pipe gallery: enter the construction of the pipe gallery after excavation in step 4; Step 6, backfill with solidified soil: After the construction of the pipe gallery is completed, backfill with the solidified soil retained in Step 4. 2 . The method for constructing a pipe gallery with first curing and then excavation according to claim 1 , wherein the in-situ curing construction area in the step 1b is a trapezoid or a stepped shape. 3 . 3. The pipe gallery construction method for excavation after first curing according to claim 1, is characterized in that, described step 3 solidifying agent comprises powder or slurry, and in described step 3, soft soil moisture mass percentage is 30% ~100%, the mass dosage of the curing agent is 6% ~ 20% of the original soil mass, and the curing agent is commercially available. 4. The pipe gallery construction method of first curing and then excavating according to claim 1, characterized in that, the in-situ curing treatment in step 3 can be directly cured in situ on the cleaned site. 5. The pipe gallery construction method of first curing and then excavating according to claim 1, is characterized in that, the solidified soil excavated on the side after the excavation of the pipe gallery in the step 4 can be placed in the original supporting pile position as The permanent stress structure is used to avoid unnecessary support, and ordinary excavators can be directly used for excavation.

Images