What do you need to be proficient in tunnel surveying?

Tunnel measurement, total station is to control linearity, convergence meter to measure convergence, GPS cost is too high to be coordinated. The level can measure the monitoring and measurement of the vault sinking and the elevation control of the arch construction.

What needs to be mastered takes into account your specific work project. But no matter what the project, flashlights and walkie-talkies must be mastered.

1. Monitoring and measurement requires a level to measure the sinking of the vault, a convergence instrument to measure the convergence of the arch, and a pre-embedded stress tie rod.

2. Construction surveyors and quality inspectors need to use the total station pay-off to determine the tunnel excavation. Vertical frame, support linearity, lining size, over-under-excavation control. The level accurately controls the elevation of each structure. Tape measure, cross-sectional dimensions, Casio calculator, compiled into calculated coordinates.

Needless to say, GPS is not for construction. The design unit or the land unit owns and uses, the design unit can give you GPS points to guide the construction, if it should be due to mountain changes, man-made or doubtful reasons GPS points need to be retested, you can first coordinate with the local land department to measure a reference data, this is by ability.

In fact, the tunnel uses a total station! And the level! If anything, it's walkie-talkies and flashlights!

GPS is impossible! There should be no signal! Tunnel measurements are carried out day and night!

It is possible to release the line 24 hours a day!! The pay-off time depends on the speed of the excavation team! Generally speaking, it takes 8 hours to drill and discharge slag removal!

Just put it on the line! Repeat after that! work.

Almost. The main application is the total station, level.

Total stations should also pay attention to the problem of inverted mirrors (on the curve).

The rest of the stuff isn't much to apply yet.

Can GPS be used in the tunnel?

Learning tunnel surveying is now simple, the master teaches you, the prestige of the public is good: the technology of tunnel surveying.

First, the outside of the hole control measurement: first of all, the establishment of the outside of the plane and elevation control network, each excavation near the plane control point and elevation control point should be set up, as the basis for construction lofting.

2. Contact measurement outside the cave and inside the hole: according to the results of the control measurement outside the hole, calculate the coordinates and elevation of the control point of the hole, calculate the design coordinates and elevation of the point to be fixed in the hole according to the design requirements, and stake out the point to be fixed in the door, which is the contact measurement outside the hole and the inside of the hole (also known as the measurement of entering the hole). The cave survey introduces the coordinates, direction and elevation outside the cave into the tunnel, so that a unified coordinate and elevation system is established inside and outside the cave.

3. Control measurement in the cave: including plane control measurement and elevation control measurement in the cave.

Fourth, the construction survey in the tunnel includes: the construction lofting of the door, the measurement of the center line of the hole, the measurement of the waist line, the measurement of the tunneling direction, the construction lofting of the excavation section and the structure.

5. Displacement observation in tunnel construction: It mainly solves the internal displacement changes and strain development laws of surrounding rock and structural buildings, as well as the relative displacement changes between various points of the tunnel wall.

1) Determination of surface subsidence of shallow buried tunnels: shallow buried tunnels are usually located in weak broken rock strata, with poor stability, in V-level surrounding rock, when the thickness of the tunnel overburden is less than 20m for single-line tunnels and less than 40m for double-line tunnels, the tension zone of the surrounding rock of the arch is often connected in the construction, and this tensile cracking failure situation becomes the main threat to the stability of the cave. Monitoring measurements of surface settlement must be carried out,** hazards that may occur.

Generally, the site is buried and the marker is observed by a precision level.

2) New Austrian construction deformation observation: tunnel deformation observation is carried out to determine the stability of the surrounding rock and grasp the support effect; It is the basis for confirming or correcting the pre-designed support parameters; It is the basis for the verification and improvement of construction methods; It is necessary to carry out the work throughout the construction process. Generally, the site adopts the buried star-shaped observation point and the convergence instrument is used to observe.

6. Completion surveying includes: tunnel section clearance measurement, centerline, elevation measurement and control centerline foundation pile and permanent leveling point measurement.

After the completion measurement, the following charts are generally required: tunnel length table, clearance table, tunnel backfill section diagram, leveling point table, pile table, broken link table, slope table.

The first thing to do for tunnel surveying apprentices is to learn some theoretical knowledge, and the understanding of tunnels must be mastered, and then how to measure also needs to be learned in books or computers. Let yourself have a foundation in your heart, and then combine it with theory to think when you actually do it, so that you can learn faster.

It is also very important to read the books that the tunnel surveying apprentice should read, read the books related to engineering surveying and tunnel surveying, and ask the master he follows if he encounters something he does not understand. In addition, it is also necessary to understand the relevant instruments, which are often used, whether it is operation or maintenance.

Hands-on

The first thing that tunneling apprentices should learn in the actual operation is the use of instruments, which is very important, and only after learning this will they continue to digest their own theories and transform the knowledge in the books into action.

It may be impetuousness at first, because the master will definitely ask you to do some coolies at first, but these coolies are also an important step in understanding the instrument. Before becoming popular, you must learn to set up a good shelf for the master, look at the instruments used, and write down what the master teaches.

Tunnelling is an important step in tunnelling engineering, and the skills required in this area are very high. Therefore, if you are an apprentice, you must start from the most basic and grasp the operation of each step.

Hold up the ruler, set up a good shelf, look at the instrument, the master let you do what you do, listen to what you say, write it down, because a lot of things you don't understand before you don't refute with your own opinions, this is the key to doing a good job, and then read some books on surveying and surveying, such as digital mapping principles and methods, engineering surveying, tunnel surveying, these books are very practical, high school knowledge is no problem, the first two must be thoroughly understood, are some principle books, basically some problems in engineering are no problem, Then find some surveying books linked to civil engineering, this aspect of the book is very much linked to the actual project, very practical, as for the surveying and mapping of other books, don't read, you don't understand, and for your work is not very useful, in this is to learn the level and total station, these two instruments do a good job of measuring most of the engineering application is no problem, look at what instruments you use on the site, search for instructions on the line, the total station is more difficult, the level is simple, the principle is understood, there is no problem, do not understand more ask the master, and then read more principle books, I personally think, do a good job, fast more than half a year to get started, a year or so to dare to lead people to do it, provided that you really spend effort to read those books and learn those instruments, slow down for about two years, but also to see how the master with you is, come on, do well, can help you so much, pure hand, hope to adopt! ac

Tunneling techniques are useful for you.

Know the main workmanship process of the tunnel: the tunnel measurement starts from the cave door, mainly including the slope of the open hole, and the measurement method is the same as that of the roadbed. Dark hole excavation, construction measurement is generally divided into upper and lower guide pit measurement, not completely according to the design.

Initial support, I-beam positioning, if there is a small side wall, the second lining only needs to set the elevation, otherwise it is similar to the initial support. There are also inverted arches and inverted arch infill surfaces.

In addition to following the master, you also have to constantly learn new measurement techniques by yourself. At that time, I was a very fast learner. Less than half a year.

And it can be said that there is zero foundation. I changed 3 masters halfway and accumulated a lot of knowledge on the construction site. After all, changing masters means changing construction sites.

And, more importantly, having a learning platform has helped me a lot. Even then, most of the knowledge was learned on that. I remember that it seems to be a technology called tunnel surveying, which is easy for the public to maintain.

1. Carry out control measurement outside the cave.

First of all, we should establish the plane and elevation control network outside the hole, and the plane control points and elevation control points should be set up near each opening, and serve as the basis for construction lofting.

2. Carry out contact measurement outside the cave and inside the cave.

According to the results of the control measurement outside the hole, the coordinates and elevation of the control point of the hole are calculated, and the different coordinates and elevations of the design of the point to be fixed in the hole are calculated according to the design requirements, and the point to be fixed in the door is collapsed and staked out, which is the contact measurement outside the hole and the inside of the hole.

3. Carry out control measurements in the cave.

The control measurement in the cave mainly includes the plane control measurement in the cave and the elevation control measurement in the cave forest belt crack.

4. Carry out construction surveys in the tunnel.

The construction survey in the tunnel mainly includes: the construction lofting of the tunnel door, the measurement and design of the waist line, the measurement and design of the tunneling direction, the measurement of the center line in the tunnel, the construction lofting of the excavation section and the structure.

Tunnel. A tunnel is an engineering building that is buried in the ground; Tunnels are a form of human use of underground space. Tunnels can be divided into hydraulic tunnels, municipal tunnels, traffic tunnels, and mining tunnels according to their uses.

Ground control measurements.

Ground control surveys mainly include plane control surveys and elevation control surveys. The main task of plane control measurement is to determine the plane position of each opening control point, so as to guide the design direction underground according to the opening control point, guide the tunnel excavation, and can penetrate according to the specified accuracy.

The following methods are generally adopted for plane control measurement: direct alignment method, traverse method, triangulation method and GPS method. The task of elevation control measurement is to measure the height difference between the leveling points near the excavation entrance in the two phases according to the design accuracy, so as to lead the unified elevation system of the whole tunnel into the cave, ensure the correct penetration in the elevation according to the specified accuracy, and ensure the correct construction of the tunnel project in the elevation.

Generally, grade level measurement is used in flat areas, and photoelectric ranging triangular elevation measurement is used in hilly and mountainous areas.

Tunnel construction surveys.

1) Measurement of the traverse in the cave and calibration of the entry point.

The construction wire is a kind of wire laid out in the tunnel construction for the convenience of lofting and guiding the excavation face, and the wire point is set while excavating, usually laid along the middle line, and the side length is generally 25 50m. The construction unit also needs to lay the opening point, the entrance point uses the design coordinates and the coordinates of the opening point, adopts the total station or theodolite to calibrate by the polar coordinate method, and the entrance point is equipped with an instrument; Then, the azimuth angle obtained by the polar coordinates is used to calculate the direction, and the distance is measured to determine the entry point.

2) Midline measurement.

Centerline measurement is an important measure to ensure that the tunnel is constructed according to the design requirements. Depending on the construction method, the width of the excavation, and the size of the curve design radius, the method of measuring the center line is also different. Due to the particularity of the materialist method at the entrance of the cave, the median line is divided into a temporary medial line and a permanent median line.

When the tunnel is excavated for about 20m, the temporary center line point should be re-checked and calibrated, and the permanent center line should be calibrated after the inspection meets the requirements. The midline measurement of straight tunnels usually adopts theodolite forward and inverted mirror method, aiming method and laser pointing instrument guidance method.

3) Penetration measurement.

Breakthrough measurement is carried out to make two or more excavation faces correctly connected at a predetermined location according to their design requirements. The following principles should be followed in the penetration measurement: the penetration accuracy should be ensured while determining the correct measurement scheme and measurement method; Each measurement should be checked objectively and independently to prevent errors.

The measurement of the actual deviation after penetration is mainly as follows.

Determination of deviation in the horizontal plane of the roadway: the center line of the roadway at both ends is extended to the joint surface of the roadway through with a theodolite, and the distance between the two center lines is measured, and its size is the actual deviation in the horizontal plane.

Determination of the deviation in the vertical plane of the rolling roadway when the roadway is penetrated: the known elevation control points in the roadway at both ends are measured by level measurement or triangulation elevation measurement, and the elevation closure difference is obtained, which actually reflects the measurement accuracy of the through elevation.

Determination of the actual deviation in the shaft after the shaft is penetrated: after the shaft is penetrated, the center weight ball line can be hung from the ground or from the middle of the upper level of the well to the lower level, and the deviation value between the centers of the shaft can be directly measured, which is the actual deviation value of the shaft penetration.

1. Lofting of the section to be measured.

It can release the center line of the road, the center line of the tunnel or the point of any width from the center line of the road, and record the ground elevation, the distance from the center line of the line to the station of the section to be measured, etc.

2. Cross-sectional measurement.

The instrument is placed in the section to be measured, (the verticality disk is set to the zenith direction to be 0 degrees, clockwise note) the telescope is aimed at another wire point or the center line point is set backwards, and the instrument is aimed at the normal direction of the line edge, which is to ensure the vertical angle reading of the measurement, the line center line side is 270-360 degrees, and the line side side is 0-90 degrees. Record the height of the instrument, the vertical angle of the observation, and the oblique distance. According to personal habits, horizontal distances and height differences can also be recorded.

If there is a large disturbance in the tunnel, you can adjust the vertical dial to 90 degrees or 270 degrees before the instrument is oriented, set the level on the leveling point, and read the tower ruler reading to tease the orange to check the line of sight.