How to calculate the verticality of percussion cast in place pile

Perpendicularity is generally expressed in . If the questioner asks the question, if it is mm, it is estimated that it is the deviation of the center of the pile.

How can you calculate the verticality directly without measuring it with an instrument? Generally, you have to use a hole detector to measure, one is mechanical, this detector is easy to cause collapse and stuck holes, and the measurement accuracy is not high, the operation is very troublesome to test a very slow, except for the cheaper point has no advantages.

The other is based on the principle of ultrasonic non-contact measurement, this instrument is convenient to use and fast, such as Wuhan Tianchen Weiye Geophysical Exploration Company's ultrasonic hole forming and slotting detector, which can automatically measure the verticality, drilling diameter, hole depth, hole wall condition and other parameters, fully automatic measurement and automatic generation of electronic construction parameters, print it out, very convenient, no need to calculate it at all.

The ultrasonic hole forming detector uses ultrasonic reflection technology, which can be used for the comprehensive detection of the quality of holes and grooves such as various cast-in-place piles (or underground diaphragm walls). In practice, the ultrasonic sensor is lowered at a certain rate along the drilling center filled with mud, and in the process of probe lowering, the ultrasonic pulse reflection signal of the vertical hole wall in four directions (or two directions) is received and recorded, and the hole wall status can be easily monitored in the four directions of the hole at the same time, and the parameters such as the width of the continuous wall groove, the diameter of the borehole, the verticality, and the condition of the hole wall can be intuitively observed.

The vertical requirement for bored pile holes is: a hole depth of 1% inclination. That is, it is one hundredth of the pile length of the allowable tilt deviation. and not more than 500mm.

To put it simply, the number of hole deviations is reduced to the total hole depth (if the actual hole center is 4 cm away from the design, and the actual hole depth is 40 meters, then his vertical inclination is.

Percussion drilling, punching and grabbing drilling and rotary drilling into holes can all be used mud wall protection construction method. The process of this construction method is:

Leveling the site, preparing the mud, burying the casing, laying the working platform, installing the drilling rig and positioning, drilling into the hole, cleaning the hole and checking the quality of the hole, lowering the reinforcement cage, pouring the underwater concrete, pulling out the casing, and checking the quality.

Bored pile is a construction method of foundation treatment in building cavity accompaniment, which is now very common and gradually integrated into on-site construction, and is common in every engineering field.

1) Compacting and leveling the construction site.

2) When installing the drilling rig, the flatness of the drilling and the vertical straightness of the active drill pipe should be strictly checked, and the verticality of the active drill pipe should be checked regularly during the drilling process, and the deviation should be adjusted immediately.

3) Regularly inspect drill bits, drill pipes, and drill pipe joints, and repair or replace them in time if problems are found.

4) Drilling at the interface of soft and hard soil layers or inclined rock surface should be drilled at low speed and low drilling pressure. If the borehole is found to be deflected, the clay should be backfilled in time, and then drilled at low speed and low drilling pressure after leveling.

5) Drilling in complex formations, if necessary, add a collator on the drill pipe.

6) Adjust the direction of the drill bit when encountering the hard soil layer and closing the town during drilling, and the drilling pressure is too high to make the drill bit uneven, resulting in timely correction of deviation.

Calculation of punched piles:

Effective pile length = design pile top elevation - pile bottom elevation.

Pile cage length = hole depth + anchorage length + plus total length of welding + length of staggered joints Total length of reinforcement cage = effective pile length + length of reinforcement lap Anchorage length Arithmetic concrete theory square = design pile length + cross-sectional area of over-irrigation height.

Theoretical quantity: final hole depth radius radius.

Filling coefficient k:

Actual square quantity: final hole depth radius radius filling coefficient k volume (square quantity) = cross-sectional area of the pile hole x (distance from the conduit to the bottom of the hole (depth of the conduit embedded in the concrete (1m)) + height of the concrete in the conduit (hole depth

Hole depth = length of main drill pipe + length of auxiliary drill pipe + length of drill bit - machine height - remaining foot pile bottom elevation bright circle = ground elevation - hole depth.

Effective key pile length = design pile top elevation - pile bottom elevation.

Elevation of the top of the reinforcement cage = design pile top elevation + anchorage length (35d for the bearing pile, 40d for the uplift pile) and the length of the suspension bar = the elevation of the machine table surface - the elevation of the top of the reinforcement cage.

Table elevation = ground elevation + machine height.

Theoretical square quantity of concrete = pile cross-sectional area (effective pile length + over-irrigation height) filling coefficient = actual square quantity Theoretical square quantity.

The length of the reinforcement cage = the elevation of the top of the reinforcement cage - the elevation of the bottom of the reinforcement cage (the reinforcement cage placed at the bottom: the bottom elevation of the reinforcement cage = the elevation of the pile bottom).

Hello, I am glad to answer the allowable deviation of cast-in-place piles for you, due to the different hole-forming processes, there are some differences. See JGJ94-2008 "Technical Code for Building Pile Foundation".

Effective pile length = design pile top elevation - pile bottom elevation.

Theoretical quantity: final hole depth radius radius.

Filling coefficient k:

Actual square quantity: final hole depth radius radius filling coefficient k volume (square quantity) = cross-sectional area of the pile hole x (distance from the conduit to the bottom of the hole (depth of the conduit embedded in the concrete (1m)) + height of the concrete in the conduit (hole depth

Hole depth = length of main drill pipe + length of auxiliary drill pipe + length of drill bit - machine height - elevation of pile bottom = ground elevation - hole depth.

Effective pile length = design pile top elevation - pile bottom elevation.

Elevation of the top of the reinforcement cage = design pile top elevation + anchorage length (35d for the bearing pile, 40d for the uplift pile) and the length of the suspension bar = the elevation of the machine table surface - the elevation of the top of the reinforcement cage.

Table elevation = ground elevation + machine height.

Theoretical square quantity of concrete = pile cross-sectional area (effective pile length + over-irrigation height) filling coefficient = actual square quantity Theoretical square quantity.

The length of the reinforcement cage = the elevation of the top of the reinforcement cage - the elevation of the bottom of the reinforcement cage (the reinforcement cage placed at the bottom: the bottom elevation of the reinforcement cage = the elevation of the pile bottom).