Hard rock tunnel chamber conversion non-explosion construction method based on automatic stress monitoring

Abstract

The invention relates to the field of tunnel construction, in particular to a hard rock tunnel chamber conversion non-explosive construction method based on automatic stress monitoring, which is characterized in that a small-section auxiliary channel is used for jacking into a large-section tunnel, a double-layer primary support arch structure and non-explosive mechanical excavation are adopted, and an automatic stress monitoring technology is combined, so that the tunnel chamber conversion non-explosive construction method is realized. And safe, efficient and environment-friendly tunnel chamber conversion construction is achieved. According to the method, vibration and shock waves caused by blasting construction are avoided, and damage to surrounding rock masses and structures is reduced; the non-explosive mechanical excavation adapts to the hard rock condition, the double-layer primary support structure reduces the arch replacement construction, and the overall efficiency is improved; dust and noise pollution is reduced, and the environment-friendly requirement is met; automatic stress monitoring ensures accurate control of the construction process, and the stability and durability of the tunnel are improved.

Description

Technical Field

[0001] The present invention relates to the field of tunnel construction, and in particular to a non-explosive construction method for converting a hard rock tunnel chamber based on automated stress monitoring. Background Art

[0002] In the construction of hard rock tunnel chamber conversion, the traditional method is blasting excavation. However, blasting construction has many disadvantages. First, the huge vibration and shock wave generated by blasting construction will damage the surrounding rock mass and existing structures, affecting the safety and stability of the tunnel and surrounding buildings. Secondly, the dust and noise pollution generated by blasting construction are serious, which has an adverse impact on construction personnel and the surrounding environment. In addition, blasting construction has poor adaptability to geological conditions. Especially under complex geological conditions, the blasting effect is difficult to control and the construction risk is high.

[0003] In order to overcome the shortcomings of traditional blasting construction, non-blasting construction methods have gradually received attention in recent years. However, there are still some problems with the existing non-blasting construction methods. For example, the excavation efficiency of some non-blasting machines in hard rock tunnels is low, which makes it difficult to meet the requirements of the construction progress; at the same time, the monitoring of surrounding rock pressure and initial support stress during the construction process is not timely and accurate enough, making it difficult to adjust the construction process in time to ensure construction safety and quality.

[0004] Therefore, there is an urgent need for a safer, more efficient and environmentally friendly hard rock tunnel chamber conversion construction method to overcome the shortcomings of existing technologies and meet actual engineering needs. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring, aiming to achieve safe, efficient and environmentally friendly hard rock tunnel chamber conversion construction through key technologies such as double-layer primary support arch structure, non-explosive mechanical excavation and automated stress monitoring.

[0006] To achieve the above object, the present invention provides the following technical solution: a non-explosive construction method for converting a hard rock tunnel chamber based on automated stress monitoring, comprising the following steps:

[0007] a. Set up a small-section auxiliary passage and enter the large-section tunnel chamber by lifting the top;

[0008] b. A double-layer primary support arch structure is used in the cantilevered tunnel, including a cantilevered section portal frame and a large-section tunnel main body primary support, wherein the cantilevered section portal frame is used for preliminary support, and the large-section tunnel main body primary support is used for final support;

[0009] c. The bottom of the cantilever channel is set with a corresponding longitudinal slope according to the cantilever angle and the arch height of the large-section chamber to ensure the applicability of the initial support trolley without modification;

[0010] d. Use non-explosive machinery to excavate the top channel and large-section chamber, specifically use a modified short-arm high-power breaker for excavation;

[0011] e. During the chamber conversion process, conventional construction monitoring and automated stress monitoring are combined to monitor the surrounding rock pressure and initial support stress in real time, and the construction process is adjusted and optimized based on the monitoring data to achieve dynamic design and dynamic construction.

[0012] Optionally, in a double-layer primary support arch structure, the top section gantry and the primary support of the large-section tunnel body are overlapped through reserved space to form an overall support system.

[0013] Optionally, in the non-explosive mechanical excavation step, the modified short-arm high-power breaker has a main arm length of 4.2m, a second arm length of 2.8m, and a total power of 300kw, which is suitable for excavation of hard rock tunnels with surrounding rock strength between 15MPa and 60MPa.

[0014] Optionally, in the automated stress monitoring step, a vibrating-wire earth pressure cell and a vibrating-wire steel stress gauge are used as monitoring equipment to monitor the surrounding rock pressure and initial support stress in real time, and the monitoring data are sent to a monitoring center for analysis and processing via wired or wireless means.

[0015] Optionally, automated stress monitoring equipment is arranged on the contact surface between the primary support and the surrounding rock and on the steel frame. The monitoring data is used to evaluate the safety and stability during the chamber conversion process, and the construction process is adjusted in time according to the monitoring results.

[0016] Optionally, it also includes construction quality control steps to ensure that the excavation section dimensions meet the design requirements, strictly control the advance of each cycle, carry out initial support in a timely manner, reduce soil exposure time, and conduct strict inspections on tunnel penetration errors, anchor bolt placement, shotcrete construction, etc.

[0017] Optional safety measures may also be included, including organizing three-level safety briefings, appointing full-time safety officers to conduct on-site inspections, strictly observing labor discipline, ensuring that construction machinery and equipment are in a safe state, strengthening monitoring and measurement of the construction process, and setting up warning signs and fire-fighting equipment.

[0018] Optionally, environmental protection measures are also included, including reasonable arrangement of construction machinery operations, control of noise pollution, treatment of sewage discharge, reduction of dust pollution, and setting up sufficient temporary sanitary facilities.

[0019] Optionally, this method is applicable to the access construction of subway station construction passages to the main chamber of the station, the construction of the main tunnel or shield machine dismantling tunnel through the construction passage, and the access construction of the auxiliary passages of the subway station from outside the tunnel to inside the tunnel to the main body of the station.

[0020] The beneficial effects of the present invention are:

[0021] 1) The present invention avoids the huge vibration and shock wave generated by blasting construction by adopting non-explosive mechanical excavation, significantly reduces the risk of damage to the surrounding rock mass and existing structures, and improves the safety during the construction process; at the same time, combined with automated stress monitoring, it can monitor the surrounding rock pressure and initial support stress in real time, timely discover and deal with safety hazards, and ensure construction safety;

[0022] 2) The non-explosive mechanical excavation method of the present invention is suitable for hard rock tunnel construction, especially the application of a modified short-arm high-power breaker, which improves the excavation efficiency in a narrow space and shortens the construction period; in addition, the setting of the double-layer primary support arch structure reduces the arch replacement construction and over-excavation backfill volume, further improving the construction efficiency;

[0023] 3) The non-explosive mechanical excavation of the present invention reduces dust and noise pollution, which meets the requirements of modern engineering construction for environmental protection; at the same time, by rationally arranging the operation of construction machinery and controlling sewage discharge, the impact of construction on the environment is further reduced;

[0024] 4) Although the initial investment in non-explosive machinery and automated monitoring equipment is relatively high, in the long run, the overall cost control is more reasonable due to the reduction of damage and repair costs caused by blasting construction, as well as environmental governance costs; in addition, the improvement of construction efficiency also indirectly reduces labor costs and time costs;

[0025] 5) The application of the automatic stress monitoring technology of the present invention makes the surrounding rock pressure and initial support stress data during the construction process more accurate and timely, which helps the construction personnel to adjust the construction process according to the monitoring results and ensure the quality of tunnel excavation and support; at the same time, the double-layer initial support arch structure also enhances the overall stability and durability of the tunnel;

[0026] 6) The method of the present invention is applicable to a variety of geological conditions and construction environments. In particular, under complex geological conditions, the combination of non-explosive mechanical excavation and automated stress monitoring can more flexibly cope with uncertainties and challenges in construction.

[0027] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 It is a construction process diagram of the present invention. DETAILED DESCRIPTION

[0030] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0031] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0032] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances. Specific embodiments

[0034] See also Figure 1 It is a non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring. It is applied to the Qixinggang Station of Chongqing Rail Transit Line 18 North Extension Project. The station is located under the main street of Pipa Mountain. It is a two-story underground station with a total length of 223m, a width of 25.9m, an excavation height of 22.27m, and an excavation area of ​​492.5m. 2 The station is buried deep, and the thickness of the tunnel vault cover layer is about 54.4m to 83.3m, of which the overburden thickness is about 52.4m to 80.3m. The surrounding rock is interlayered with sandstone and mudstone, with mudstone as the main layer. The comprehensive surrounding rock grade is Grade IV. The main tunnel construction of the station adopts 1 main + 1 auxiliary construction channel to enter the main tunnel of the station. The construction method includes the following steps:

[0035] 1. Construction preparation

[0036] Before construction, carry out detailed geological surveys and surrounding environmental surveys, formulate detailed construction plans and safety measures, and prepare the necessary construction machinery and materials, including modified short-arm high-power breaker, wet spraying manipulator, vibrating wire earth pressure cell, vibrating wire steel stress meter, etc.

[0037] 2. Construction of the top channel

[0038] Step 1: At the junction of the auxiliary passage and the main tunnel of the station, construct the cantilever opening according to the design requirements. At the starting position of the cantilever opening, three steel frames are closely arranged, and vertical I-beam supports and I-beam crossbeams are set as the support points of the main steel frame.

[0039] Step 2: Use a modified short-arm high-power breaker to excavate the steps on the top channel, set up a portal steel frame according to the height change, and promptly apply the first layer of initial support. The spacing of the portal steel frame of the top channel is set to 0.75m, and the top excavation contour line is raised from the top of the auxiliary channel at an angle of 15° to the designed station main arch position.

[0040] In this embodiment, the portal steel frame in step 2 is set according to the height variation.

[0041] Step 3: After the excavation of the steps on the cantilevered passage is completed, remove the sprayed concrete on the inside of the portal steel frame to strengthen the connection between the two layers of primary supports.

[0042] 3. Initial support construction of large chamber

[0043] Step 4: Carry out the construction of the initial support steel frame of the large chamber. The arch foot of the initial support arch frame of the large chamber tunnel is supported on three closely spaced steel frames and is firmly welded to the supporting portal steel frame through the footing steel plate. At the same time, a locking foot anchor pipe is installed at the end of the main tunnel steel frame to ensure the stability of the steel frame.

[0044] In this embodiment, the main arch steel frame of the station is installed in sections according to the progress of climbing the stairs.

[0045] Step 5: Spray the main body's initial support concrete, using a wet spraying robot to perform the spraying operation to ensure that the concrete is sprayed evenly and densely.

[0046] 4. Construction of steps under the cantilevered passage

[0047] Step 6: Dig the steps under the cantilevered passage and extend the steel frame support of the door opening side walls to complete the excavation and support of the door opening.

[0048] 5. Automated stress monitoring

[0049] Step 7: Set up a vibrating wire earth pressure cell at the contact surface between the primary support and the surrounding rock, and add a vibrating wire stress gauge on the steel frame to monitor the surrounding rock pressure and steel frame stress in real time. The monitoring data is sent to the monitoring center via wired or wireless means, and processed and analyzed by dedicated computer data analysis software.

[0050] Step 8: According to the automated stress monitoring data, timely adjust the construction process to ensure the safety and stability of the construction process. When the monitoring data exceeds the warning threshold, immediately activate the alarm mechanism and take corresponding safety measures.

[0051] 6. Excavation of main branch tunnels

[0052] Step 9: After the monitoring data is stable, follow the excavation sequence of the main tunnel of the station, and carry out the cutting of the portal steel frame columns, the construction of the arch steel frame of the upper section of the station, and the spraying of concrete. During the excavation process, continue to carry out automated stress monitoring to ensure construction safety.

[0053] 7. Construction quality control and safety measures

[0054] During the entire construction process, the excavation section size is strictly controlled to ensure that it meets the design requirements. The monitoring and measurement of the construction process are strengthened, and the settlement of the arch and the convergence of clearance are continuously observed.

[0055] Appoint full-time safety officers to conduct on-site inspections and strictly abide by labor discipline and safety operating procedures. Strengthen the management and maintenance of construction machinery and equipment to ensure that the equipment is in good condition.

[0056] 8. Environmental protection measures

[0057] Reasonably arrange the operation time of construction machinery to reduce noise pollution. Centrally treat sewage and discharge it after it meets the standards. Strengthen dust management at the construction site and take measures such as sprinkling water to reduce dust.

[0058] Through the above specific embodiments, the successful application of the non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring in the Qixinggang Station of the Chongqing Rail Transit Line 18 North Extension Project has proved the significant advantages of this method in improving construction safety, improving construction efficiency, and enhancing environmental protection performance.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring, characterized in that: The following steps are involved: a. Set up a small-section auxiliary passage and enter the large-section tunnel chamber by lifting the top; b. A double-layer primary support arch structure is used in the cantilevered tunnel, including a cantilevered section portal frame and a large-section tunnel main body primary support, wherein the cantilevered section portal frame is used for preliminary support, and the large-section tunnel main body primary support is used for final support; c. The bottom of the cantilever channel is set with a corresponding longitudinal slope according to the cantilever angle and the arch height of the large-section chamber to ensure the applicability of the initial support trolley without modification; d. Use non-explosive machinery to excavate the top channel and large-section chamber, specifically using a modified short-arm high-power breaker for excavation; e. During the chamber conversion process, conventional construction monitoring and automated stress monitoring are combined to monitor the surrounding rock pressure and initial support stress in real time, and the construction process is adjusted and optimized based on the monitoring data to achieve dynamic design and dynamic construction.

2. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring according to claim 1 is characterized in that: In the double-layer primary support arch structure, the top section gantry and the primary support of the large-section tunnel body are overlapped through reserved space to form an overall support system.

3. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring according to claim 1 is characterized in that: In the non-explosive mechanical excavation step, the modified short-arm high-power breaker has a main arm length of 4.2m, a second arm length of 2.8m, and a total power of 300kw, which is suitable for excavation of hard rock tunnels with surrounding rock strength between 15MPa and 60MPa.

4. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring according to claim 1 is characterized in that: In the automated stress monitoring step, vibrating-wire earth pressure cells and vibrating-wire steel stress gauges are used as monitoring equipment to monitor the surrounding rock pressure and initial support stress in real time, and the monitoring data are sent to the monitoring center for analysis and processing via wired or wireless means.

5. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring as claimed in claim 4, characterized in that: Automated stress monitoring equipment is arranged on the contact surface between the primary support and the surrounding rock and on the steel frame. The monitoring data is used to evaluate the safety and stability during the chamber conversion process, and the construction process is adjusted in time according to the monitoring results.

6. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring according to claim 1 is characterized in that: It also includes construction quality control steps to ensure that the excavation section dimensions meet the design requirements, strictly control the advance of each cycle, carry out initial support in a timely manner, reduce the soil exposure time, and conduct strict inspections on tunnel penetration errors, anchor placement, shotcrete construction, etc.

7. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring according to claim 1 is characterized in that: It also includes safety measures, including organizing three-level safety briefings, setting up full-time safety officers to conduct on-site inspections, strictly observing labor discipline, ensuring that construction machinery and equipment are in a safe state, strengthening monitoring and measurement of the construction process, and setting up warning signs and fire-fighting equipment.

8. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring according to claim 1 is characterized in that: It also includes environmental protection measures, including the reasonable arrangement of construction machinery operations, the control of noise pollution, the treatment of sewage discharge, the reduction of dust pollution, and the establishment of sufficient temporary sanitary facilities.

9. The non-explosive construction method for hard rock tunnel chamber conversion based on automated stress monitoring according to claim 1 is characterized in that: This method is applicable to the construction of subway station construction passages connected to the main chamber of the station, the construction of the main tunnel or shield machine dismantling tunnel through the construction passage, and the construction of the auxiliary passages of the subway station from outside the tunnel to inside the tunnel connected to the main body of the station.

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