Data analysis (mainly principles and advantages)
The ultrasonic detection probe is small, and the field operation is very convenient. Unless the shape deviation of the pile hole or the groove wall is too large (more than half of the pile diameter or groove width from the center), the probe generally does not touch the side wall, and the test result is relatively intuitive.
Aperture calculation (ultrasonic method)
Ultrasonic testing equipment generally has an automatic mapping function. The software inside the instrument has calculated the distance measurement and the probe size, and can directly read the distance between the center of the transducer and the wall of the hole (slot) from the hole (groove) sectional view.
However, when using the ultrasonic instrument with automatic mapping function to measure the hole, since the probe position is not necessarily at the center of the hole, the hole wall distance displayed on the sectional view is not necessarily equal to the aperture (as shown in Fig. 3), and the measured aperture D can be caculated as follows:
D=R1+R2
Wherein: D- the average diameter of the pile hole;
R1, R2 - The radius of pile hole;
11 - The horizontal distance of the probe transducer from the direction I to the wall of the hole;
12 - The horizontal distance of the probe transducer from the direction II to the wall of the hole;
13 - The horizontal distance of the probe transducer from the direction III to the wall of the hole;
14 - The horizontal distance of the probe transducer from the direction IV to the wall of the hole;
Verticality calculation (ultrasonic method)
X0= （l10- l20）/2
Y0= （l30- l40）/2
Xn= （l1n- l2n）/2
Yn= （l3n- l4n）/2
Wherein:
110, l20, l30, l40 - the horizontal distance between the center of the probe at the first measuring point and the four directions of the hole wall;
l1n、l2n、l3n、l4n - the horizontal distance between the center of the probe at the nth measuring point and the four directions of the hole wall;
If the eccentricity of the pile hole at the nth measuring point is En, then:
The perpendicularity of the pile hole at the nth measuring point is Kn:
Kn= (En/Hn)×100%
Wherein: Hn - the depth value at the nth measuring point.
In addition, the calculation of the eccentricity En can be calculated as follows when detecting groove wall:
Wherein: Y0, Yn - the horizontal distance between the ultrasonic probe and the groove wall at the first and nth measuring points, respectively.
Sludge thickness calculation
The portion below the inflection point on the apparent resistivity-depth curve of the mud can be judged as sediment, and its thickness is taken from the depth coordinate.
