퍼쿠션 지반조사 PERCUSSION SOUNDING

 

퍼쿠션 지반조사 PERCUSSION SOUNDING

 

영신컨설턴트 (02) 529 8803

개요

표준관입시험과 시추조사를 위해 물을 주입하여 케이싱으로 천공한다. 물이 없는 현장에서 먼 곳에서 관으로 물을 공급한다. 겨울철에는 물의 동결로 작업관이 얼어 작업이 어렵다. 무거운 케이싱과 로드을 인력을 연결하고 해체한다. 그런 문제점을 개선한 방법이 percussion souding이다. percussion souding은 percussion 헤머로 로드를 관입하여 물을 사용하지 않고 케이싱을 사용하지 않아 빠르며 노르웨이 스웨덴에서 표준조사방법으로 사용하고 있다. percussion souding은 기반암의 심도를 관입속도로 알 수 있다. 연약지반은 콘관입시험이나 벤시험을 추가한다. Geotech percussion sounding equipment can be used for the simplest to the most advanced sounding methods.

 

 

PERCUSSION SOUNDING의 종류

 

1. Percussion sounding 관입속도 측정

The objective is to recognize the depth to bedrock or hard bottom. Rods of Ø44 mm. Of the available drill bits, chisel bits are recommended (see front illustration), as they will disclose joints in rocks. In the methods below, the sounding in soil is treated independently from sounding in hard soil and rock. Parameters, table below, are added compared with the basic percussion sounding such as flushing and rotation, for redundancy and in order to appreciate soil and rock quality.

 

2. Soil-Rock Sounding (New Swedish standard) Percussion sounding + 로드회전+ 공기나 물 주입

New Swedish standard set with percussion and rotation of rods. Flushing with air, water or polymers through the drill bit. The method is also called Measurement While Drilling (MWD). Hammer should perform 0,2 to max 0,6 m/min in bedrock, Feed 5-10 kN. Rotation 40-200 rpm.

 

3. Norwegian Total Sounding

Rotary/pressure sounding (25 rpm) until drill bit stops. Increase to 50-70 rpm, then back to 25 rpm and flush borehole. Thereafter percussion drilling with water flushing, constant feed (8 kN) and rotation (25 rpm). Torque 1-1,5 kNm, Feed 40-50 kN, Rotation speed 0-200 rpm, Blow frequency 3000-3500 blows/min, Blow energy 8-10 kW, Flushing pressure min 30 bar (water) or 8 bar (air), Flushing volume 20-50 l/min (water) or 7 m3/min (air).

 

Measured parameters	1.	2.	3.
Depth Penetration resistance Penetration speed Feed Hammer pressure Hammer sensor on/off Rotation pressure Rotation speed Flushing pressure Flushing volume	X	X X X X X   X X X X	X X   X   X X X X X
1. Traditional percussion 2. Soil-Rock sounding (class 3) New Swedish standard 3. Norwegian Total sounding

 

 

수직하중 측정장치 FFM SYSTEM 2000

 

 

Improved accuracy	Static	Travelling without lo
At the yoke, with new yoke attachment	0.05 kN	< 0.04 kN
Feed force measurement at foot of feed cylinder	0.4 kN	< 0.35 kN

 

 

Improved resolution	Static
At the yoke, with new yoke attachment	0.01 kN
Feed force measurement at foot of feed cylinder	0.01 kN

 

As a comparison, the Swedish Soil/Rock Sounding requires an accuracy of 10%FS, equivalent to approximately to 10 kN in many soundings.

TECHNICAL SPECIFICATIONS:

	Rig 604	Rig 605/607/707
Max. load:	50 kN	100 kN
Measuring accuracy:	0.1% FS	0.2 % FS
Resolution:	0.01 kN	0.01 kN
Power supply:	12-15 Vdc	12-15 Vdc
Current:	<100 mA	<100 mA
Output signal:	Frequency	Frequency

 

 

회전력 측정장치 TORQUE SENSOR

Direct measurement of the effective torque

 

 

Gearbox friction is software compensated for rotational speed. More accurate values for Rotary/Percussion and Total sounding.

 

 

TORQUE SENSOR TECHNICAL SPECIFICATIONS:

Max. load:	2700 Nm
Measuring range:	+/- 1500 Nm
Measuring accuracy	< 2% FS
Resolution:	1 Nm
Power:	12-15 Vdc
Current:	<100 mA
Output signal:	Frequency

 

 

 

 

관입속도를 일정하게 하고 (20초/m) 수직하중 측정