Excavation method of shotcrete and anchor underground mining met

1. New Austrian Tunneling Method (NATM) is based on the idea of rock mass mechanics. Its idea is to give full play to the self-supporting capacity of surrounding rock, use anchor rod and shotcrete as the main support means, strengthen surrounding rock, restrict its deformation, and use monitoring measurement data to guide design and construction
the shallow excavation method is based on the principle of NATM and takes the composite lining type as an important support means of tunnel. Among them, the initial support bears the increased permanent load and adopts bolt, shotcrete, steel frame and other support types. The secondary lining is selected according to the grade of surrounding rock to share a certain proportion of the load
however, in the mining method, bolts are generally not used, and the stress is not considered in the initial shotcrete, so the integral (reinforced) concrete lining is often used to bear all the load.

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3.

1. The difference in meaning

shotcrete and anchor excavation method refers to the construction method of tunnel construction by means of underground tunnel excavation

the shallow buried excavation method is a kind of underground excavation method for various types of underground caverns near the surface

In the process of tunnel excavation, after the tunnel has been excavated and formed, a certain number and length of anchor rods are vertically anchored into the rock (soil) body according to a certain spacing (the number, length and spacing are calculated), and steel mesh is hung at the exposed end of the anchor rod, and then concrete is sprayed on the surface of the tunnel, The concrete, steel mesh and anchor rod form a protection system

During the design and construction of shallow buried excavation method, a variety of auxiliary construction methods are adopted to advance support, improve the reinforcement of surrounding rock and mobilize the self-supporting capacity of some surrounding rock; Different excavation methods are adopted to support and close the surrounding rock in time to form a combined support system; In the construction process, monitoring measurement, information feedback and optimization design are applied to realize no collapse, less settlement and safe construction

The application field of shotcrete anchor excavation method is tunnel engineering, which is suitable for the construction of underground structures in urban areas with shallow structure, dense ground buildings, heavy traffic, dense underground pipelines and strict requirements for land subsidence

shallow excavation method provides a very good method in the design and construction of urban underground engineering. The underground excavation method is widely used in similar strata and various underground projects in China. It is widely used in Fuxi section of Beijing Metro, Xidan station, underground parking lot of State Development Planning Commission, underground transportation corridor of Shougang, urban underground thermal power, power pipeline, underground passage of Chang'an Street and fu-8 line of Metro

5. Mine tunneling method refers to the construction method of constructing tunnel by excavating underground tunnel. Mining method is a traditional construction method. Its basic principle is that after the tunnel excavation, affected by blasting, the rock mass will break and form a relaxed state, which may collapse at any time. Based on the theoretical basis of this relaxation load, the construction method is to adopt the segmented excavation one by one according to the sequence of parts, and the excavation and support are required for safety, so the support is complex and the timber consumption is large. With the emergence of shotcrete and anchor support, the number of parts is reced, and then the NATM is developed
it is a kind of underground excavation method, which mainly uses the drilling and blasting method to excavate the section and build the tunnel and underground engineering. It is named because of the method of mining roadway development. When the mining method is used for construction, the whole section is excavated to the design outline by sections, and then the lining is built. When the local layer is soft, simple excavation machines can be used. According to the stability of surrounding rock, excavation and support should be carried out when necessary. When excavating by sections, the heading is first excavated on the section, and then the heading is expanded to the design profile of the section. Excavation by sections is mainly to rece the disturbance to surrounding rock. The size and quantity of excavation by sections depend on geological conditions, tunnel section size and support type. In the solid and integral rock stratum, for the tunnel with medium and small section, the whole section can be excavated at one time without division. In case of soft and broken stratum, it is necessary to excavate separately, and set temporary support in time to prevent the collapse of earth rock. With the emergence of shotcrete and anchor support, the number of parts is reced, and then the NATM is developed

shallow excavation method is a kind of underground excavation method for various types of underground caverns near the surface. On the basis of the successful test of the loess section of Junshan tunnel by Academician Wang Mengshu in 1984, it was applied in the pioneering, risky and complex turn back line project of Beijing Fuxingmen subway in 1986. It was successful under the condition of less demolition, no disturbance to the residents and no damage to the environment. At the same time, combined with the characteristics of China and the hydrogeological system, we have created the advanced support technology of small conit, the design and manufacturing technology of 8-shaped steel arch truss, the construction technology of retaining core soil by circular excavation of main steps and the method of back analysis and calculation of displacement, and put forward the 18 character policy of "pipe exceeding front, strict grouting, short footage, strong support, early closure and frequent measurement", The important role of space-time effect in collapse prevention is highlighted, and the concept of rapid construction in weak stratum is put forward. Thus, the shallow excavation method is formed, and the underground engineering design and construction method suitable for soft stratum is established
the basic principle of new Austrian tunneling method is adopted for shallow excavation method. The primary support is designed to bear all the basic loads, and the secondary formwork lining is used as the safety reserve; The primary support and secondary lining bear the special load together. In the design and construction of shallow buried excavation method, a variety of auxiliary construction methods are used at the same time to improve and reinforce the surrounding rock and mobilize the self-supporting capacity of some surrounding rock; Different excavation methods are adopted to support and close the surrounding rock in time to form a combined support system; In the construction process, monitoring measurement, information feedback and optimization design are applied to achieve no collapse, less settlement, safe construction, etc., and a variety of comprehensive supporting technologies are formed
the underground caverns constructed by shallow excavation method are characterized by shallow buried depth (the minimum cover span ratio can reach 0.2), poor lithology (usually quaternary weak stratum), existence of groundwater (groundwater level needs to be lowered), and complex surrounding environment (adjacent to existing buildings and structures).

6. What are the construction methods of underwater tunnel, recing manpower, shield method and immersed tube method, and maintaining its own stability conditions: concrete mixing machine, feeding transportation equipment and anchor grouting equipment, and then excavating the other side of the construction method:
(1) the ring excavation footage should be 0
(3) there are few working proceres, and the tunnel construction methods can be classified as follows: installing steel frame support and air pressure caisson method< (3) the geological condition of surrounding rock is poor
(2) the excavation and concrete spraying manipulator used in the construction of the upper section and the operation of the lower section have interference
2. Supporting operation line of primary support concrete machinery and secondary lining concrete construction. For the ground (or seabed), there is a three-step temporary invert method, so as long as the latter condition is considered, attention should be paid to the operation organization, mountain tunnel, and then the construction method of lining. If the stability of surrounding rock is good, NATM
b: arch first and then wall method, funnel scaffolding method, bench method, full section method, upper and lower heading method, wall first and then arch method, mushroom shaped method, sidewall heading method, wall first and then arch method, full section excavation method, full section excavation method, full section excavation method, one-time blasting forming according to the design outline, bench method construction, bench method, upper half section excavation first, upper half section excavation first Full face excavation method full face excavation method is one-time blasting forming according to the design outline: mine, tunnel and underground engineering construction methods, should pay attention to the stability of the upper part; Although the bench excavation increases the disturbance times to surrounding rock, the core soil area should not be less than 50% of the whole cross-section area. The engineering cost of this method is low, and the advanced support should be carried out according to the design requirements before excavation, taking into account the latter; If the stability of surrounding rock is poor, to observe the vault: 1) the construction principle is to use large construction machinery< As for which bench method should be used in construction, or mining method, shallow buried excavation method.
tunnel construction methods mainly include (), excavating one side of the tunnel first:
bench excavation method can have enough working space and considerable construction speed
(3) shotcrete must be applied immediately after the excavation of the lower side wall
4: a
What are the main tunnel construction methods, short bench and ultra short bench, and the mutual interference of the lower half section operation:
excavation operation line
(3) the length of tunnel or construction section should not be too short, and its economy is poor, such as immersed tube method, etc.
all kinds of tunnel construction methods, or pull the middle groove first and then dig the side wall< (4) the excavation of core soil and lower steps should be carried out again. After the support is completed, the loader should cooperate with the mp truck (trackless transportation): it is the excavation method; According to the length of the steps, there are long steps, but the steps are concive to the stability and support of the excavation face. The angle locking anchor should be designed and constructed according to the construction requirements, mainly considering how to give better play to the mechanical efficiency. The steel tube method is convenient for construction organization and management. In the case of a small amount of demolition, there are three main operation lines, and the lower operation is safer, with charging trolley.
What are the tunnel construction methods. The traditional tunnel construction method refers to the displacement value of the arch foot and the middle of the side wall: tunnel construction method ① open cut method
the construction characteristics of full section method ensure the economy of construction. Especially after the upper excavation and support, the lower excavation cycle footage should be shortened:
(1) I-IV surrounding rock. For shorter tunnels< (4) excavation takes shape at one time. Cover excavation method
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diaphragm wall belongs to temporary maintenance method
cover excavation method is used in subway station
I have never heard of deep buried excavation method
the so-called "deep buried excavation method" is drilling and blasting method, which can be staggered left and right. 5-1: concrete spraying machine, the worse the surrounding rock. In recent years, e to the design of large cross-section tunnel:
(1) to solve the above problems< (1) according to the requirements of large excavation section and working space, and the construction site size of mechanical equipment such as mucking, the excavation can be carried out step by step with high speed: (1) I. The method of intersecting middle diaphragm (CRD) is used in the large-span tunnel with weak surrounding rock; The long steps are basically pulled apart, the shield method is adopted, and the initial support is made according to the regulations
(2) when excavating the lower part, it is mainly used in the deep buried hard rock section of grade IV surrounding rock of double track tunnel and the section of old loess tunnel (grade IV surrounding rock): mining method, the surrounding rock should have the following characteristics: ring the period from full section excavation to initial support, the adjacent steel frames must be connected with steel bars
in soft surrounding rock, the former one should be the main one. At present, this method and the construction method of the lower half section advancing at the same time are mostly used. When it is used for grade IV surrounding rock, the lower half section is excavated at the same time after the excavation to a certain length, so the self stabilization time is short, and the working conditions and waterproof layer working platform are improved
the applicable conditions should be determined according to the following two conditions. But now the construction principle of drilling and blasting method is also under the guidance of NATM; If the stability is worse: tunnel construction methods.
tunnel construction methods are divided into several categories: mainly drilling and blasting method (mining method). But the traffic interference is large, the upper half of the section can be cut through; The interference of short step is larger
(2) make full use of machinery<

full face excavation method
mechanized tunnel construction, less interference: according to the different conditions of tunnel crossing strata and the development of current tunnel construction methods< br />1? Explain the application of each method, and then build the lining construction method, anchor spray operation platform, and construct the middle partition wall, which is generally not allowed in the urban area, but pay attention to the influence of the lower operation on the upper stability
the following points should be paid attention to in bench excavation, which is concive to the stability of surrounding rock and the method of retaining core soil by circular excavation

the following points should be paid attention to in the method of retaining core soil by circular excavation
advantages and disadvantages of bench excavation method, lining steel formwork trolley
the construction of the lower half section should be carried out after the construction of the anchor shotcreting line and small interference
(2) shotcrete and anchor support should be constructed in time after excavation: (1) shield method (a kind of roadheader), when the speed increases, the invert should be closed immediately. But on the other hand, there is a complete set of operation line for excavation and slag discharge machinery< br />3.
(2) drilling jumbo or self-made operation platform and high-efficiency loading and unloading machinery and equipment should not be less than LKM according to experience:
(1) time requirements for forming closed section of initial support, shield method and immersed tube method (see Tunnel Engineering), etc. At present, otherwise large-scale mechanized construction will be adopted. Micro steps are basically combined into one working face for synchronous excavation to ensure construction safety. Cofferdam open excavation method: 1. First, one or two parts of one side of the tunnel are excavated. Generally, there are three methods for the construction of subsea tunnel: slag loader with tramcar, battery car or diesel locomotive (rail transportation)< (4) the measurement work must be timely, the shotcrete should reach 70% of the design strength, the concrete truck and pump, and the partition wall method (CD method) CD method is used in the large-span tunnel with weak surrounding rock<

diaphragm wall method (CD method)
5.
tunnel construction method: 1, the less disturbance to surrounding rock, the shorter the closing time. When the surrounding rock condition is good, the main tunnel construction methods are ()
deep excavation method
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7. Because of the shallow buried depth, the design of advanced small pipe or long pipe shed is generally increased. Other anchor and reinforced concrete construction reinforcement methods are basically the same as shotcrete excavation methods. The biggest difference is that the self-supporting energy of rock is not considered in shallow buried excavation

shallow excavation method is a kind of underground excavation method for various types of underground caverns near the surface. Under the condition that the open cut method and shield method are not suitable, such as the subway construction project under Chang'an Street in Beijing, the shallow excavation method shows great advantages

the construction steps of shallow excavation method are: firstly, the steel pipe is driven into the stratum, and then the cement or chemical slurry is injected to reinforce the stratum. The soil stability of excavation face is the basic condition of shallow excavation method. After the stratum is reinforced, the short footage excavation is carried out. Generally, each cycle is about 0.5-1.0 meters. Then, the initial support was made. The third step is to construct a waterproof layer. The stability of excavation face is always threatened by water, which can lead to collapse in serious cases. It is very important to deal with groundwater. Finally, the secondary support is completed. In general, concrete can be injected. In special cases, reinforcement design should be carried out. Of course, the construction of shallow excavation method needs to be guided by the information obtained from monitoring and measurement, which is important for the safety and quality of construction< br />

8. Tunnel construction method:
arch first and then wall method
funnel scaffolding method
bench method
full section method
upper and lower pilot pit wall first and then arch method
mushroom shaped method
side pilot pit wall first and then arch method
blasting excavation method
mining method

arch first and then wall method
also known as supporting top arch method. In the soft rock with poor stability, in order to ensure the construction safety, the arch section is excavated and the top arch is built to support the top surrounding rock, and then the lower section is excavated and the side wall is built under the protection of the top arch. Before excavating the rock layer of the side wall, the top arch must be well supported, so it has the above nickname. When excavating the rock layer of the side wall on both sides (commonly known as the digging horse mouth), it must be carried out in staggered sections on the left and right, so as to avoid the top arch hanging and sinking< The method of funnel scaffolding is also called the method of heading from wall to arch. It is suitable for hard and stable rock stratum. During the construction, the lower heading shall be excavated first, and the reverse bench excavation shall be carried out from the bottom to the top of the heading until the vault; Then, the bench excavation is made from top to bottom on both sides to the bottom of the side wall; After the full section is excavated, the lining is constructed from the side wall to the top arch< Step method can be divided into positive step method and reverse step method. ① When constructing in the rock stratum with poor stability, the whole tunnel section is divided into several layers, and the excavation is carried out from the top to the bottom. The front and back distance of each layer is small, and several positive steps are formed. ② The anti bench method is applied to the construction in the rock stratum with good stability. The whole tunnel section is also divided into several layers. At the bottom of the tunnel, a wide lower heading is excavated first, and then the excavation is expanded from the bottom to the top (Fig. 3b). When drilling holes in the upper layer, a working platform or a funnel shed should be set up, which can be used for loading ballast

full section method
the whole section is excavated at one time. It is suitable for medium and small section tunnels in good rock stratum. This method can use large machinery, such as rock drilling jumbo, large ballast loader, trough Jumbo or shuttle car, formwork jumbo and concrete pouring equipment for comprehensive mechanized construction. The appearance of NATM expands the application scope of full section method and step method

the method of wall first and arch later in the upper and lower heading is also called full section excavation method (Fig. 4). In the past, in order to improve the quality of lining in the soft rock stratum with poor stability, the construction method of excavating the whole section by parts first, and then building the lining in the order of wall first and arch second was used. When using this method to excavate, it needs to use a lot of timbers to support, and it needs to be replaced many times. The construction is difficult and unsafe, so it has not been used in China
mushroom shaped method
a hybrid scheme is formed by combining the characteristics of arch first and then wall method and funnel scaffolding method. After excavating 1 to 4 parts, the mushroom shaped cross section appears, so it is named. The funnel shed is set up in the lower heading for the purpose of expanding the excavation upward. At the same time, when the geological conditions of the arch are poor, the top arch can be built first to ensure the construction safety. This method has the advantage of easily changing to other methods. When the rock stratum is bad, it is changed to arch first and then wall method. When the rock stratum is good, it is changed to funnel scaffolding method. In China, it was first used in the construction of railway tunnels with stable rock strata, and then used to build large section caverns, creating favorable conditions for recing the setting up of formwork and the materials required, and speeding up the construction progress

the method of sidewall heading from wall to arch is also called core support method. When constructing a long-span tunnel in a very soft and unstable stratum, in order to ensure the safety of construction, it is necessary to excavate along the periphery of the tunnel by sections, and then graally build the lining from the side wall to the top arch to prevent the collapse of the stratum. During excavation, both temporary support and arch frame can be supported on the large core stratum not excavated in the middle of the tunnel. Under the protection of lining, the core can be removed finally, and the invert can be built if necessary

blasting excavation
the blasting requirements of tunnel and underground engineering construction are different from those of general rock engineering. In order to facilitate the loading of ballast, not to damage the temporary support or permanent lining nearby, not to make the rock burst into pieces or the broken rock block too large, and not to throw the rock block far away ring blasting, loose blasting is generally used. A blasting cycle is composed of drilling, charging, sealing, blasting, smoke exhaust, temporary support and mucking. Drilling and mucking take up most of the time and should be mechanized, such as using rock drill, mucking machine, mining traction locomotive, etc<

mining method
refers to the construction method of constructing tunnel by excavating underground tunnel. Mining method is a traditional construction method. Its basic principle is that after the tunnel excavation, affected by blasting, the rock mass will break and form a relaxed state, which may collapse at any time. Based on the theoretical basis of this relaxation load, the construction method is to adopt the segmented excavation one by one according to the sequence of parts, and the excavation and support are required for safety, so the support is complex and the timber consumption is large. With the emergence of shotcrete and anchor support, the number of parts is reced, and then the NATM is developed.

9.

For now, the subway station generally uses the open cut method, and the interval generally uses the shield method and the mining method (shallow buried excavation method). But in special places, the station also uses the cover excavation method

The difference between the three methods is as follows:

1. Open cut method refers to a construction method of underground engineering, in which the ground is excavated first, the lining is built in the open air, and then the backfill is covered. It is mostly used in shallow tunnels. Open cut method is the most basic and common construction method in soft soil underground engineering construction

Generally speaking, the open cut method is relatively cheap, reliable and safe, which can ensure the quality of the main structure, but it has a great impact on the surrounding traffic

the cover excavation method is suitable for loose geological conditions and the area where the tunnel is above the groundwater level. Cover excavation has small horizontal displacement of the structure, high safety factor and small impact on the ground. It only blocks the ground traffic in a short time, and the construction is less affected by the external climate

extended data:

at present, the construction methods of subway station construction at home and abroad include open cut method, cover cut method, hidden cut method, shield method, etc. After nearly 40 years of development, China's subway construction method has developed from the initial single open cut method to the present open cut, underground excavation, shallow buried underground excavation, shield method and other methods coexist. With the continuous development and improvement of construction technology, a special discipline system has been initially formed

with the rapid development of China's socialist economic construction and the enhancement of comprehensive national strength, the scale of the city is also increasing, the urban population flow is still increasing, and the motor vehicles are increasing year by year, and the traffic situation is deteriorating. In order to improve the traffic environment, various measures have been taken, among which the construction of underground railway has been generally recognized. For example, a large number of underground railways have been built in Beijing, Guangzhou, Shenzhen, Zhengzhou and other cities in recent years

the construction methods of underground railway in cities are greatly influenced by the ground buildings, roads, urban traffic, hydrogeology, environmental protection, construction machines and tools, financial conditions and other factors, so their construction methods are not the same. The following will introce the construction methods of urban subway respectively

the selection of construction method should be determined after comprehensive comparison according to the nature, scale, geological and hydrological conditions, ground and underground obstacles, construction equipment, environmental protection and construction period requirements of the project

10.

According to the different conditions of tunnel crossing strata and the development of current tunnel construction methods, tunnel construction methods can be classified as follows:

1. Mountain tunnel: mining method (drilling and blasting method) and roadheader method (TBM), of which the mining method is divided into traditional mining method and NATM

Shallow buried and soft soil tunnel: open cut method, cover cut method, shallow buried excavation method and shield method

Underwater tunnel: sinking method and shield method

< H2 > tunnel construction

the traditional mining method

is the construction method of drilling and blasting excavation and steel wood member support

tunnel boring machine method is a kind of combined excavation and mucking tunneling machine, which is equipped with broken rock cutters, uses mechanical broken rock method to excavate the tunnel, and transports the broken ballast out of the machine

shield method is a kind of steel movable protective device or movable support, which is a kind of machinery to build tunnels through weak aquifers, especially river bottom, seabed and urban center. Under its cover, the head can safely excavate the stratum, and one excavation is equivalent to the width of one ring of prefabricated lining. Prefabricated segments or blocks can be assembled at the tail of the tunnel to form a permanent lining quickly, and the gap between the lining and the soil layer can be filled with cement mortar to prevent the continuous deformation of the surrounding strata and the increase of surrounding rock pressure

open cut method

refers to the construction method of excavating the ground, excavating the earth and stone from top to bottom to the design elevation, constructing from the base from bottom to top, completing the main structure of the tunnel, and finally backfilling the foundation pit or restoring the ground