In-situ-testing

STANDARD PENETRATION TEST(SPT)

STANDARD PENETRATION TEST(SPT)

The standard penetration test (SPT) is an in-situ dynamic penetration test designed to provide information on the geotechnical engineering properties of soil. The test provides samples for identification purposes and provides a measure of penetration resistance which can be used for geotechnical design purposes.

GOSCO equips SPT equipment with drilling machine and performs this kind of test during drilling process. We provide the SPT service with competitive costs.

Thí nghiệm xuyên tiêu chuẩn (SPT) - Thí nghiệm hiện trường

Steps to perform the SPT test:

– Step 1: Drill to the test depth, cleaning & dredged muck from bottom of the borehole, and install equipment according to standards.

– Step 2: Mark 3 equal intervals (15cm) on the drliing rod.

– Step 3: Release the donut hammer in free fall and count the total number of hammers through the marked segments.

– Step 4: Take the hammer number of the last 2 segments as SPT index

– Step 5: Uninstaling SPT inquipment and remove SPT sample, repeat the steps when performing the experiment at the next times.

Thí nghiệm xuyên tiêu chuẩn - Standard penetration test (SPT)

Figure 1:Standard Penetration Test

 

Thí nghiệm xuyên tiêu chuẩn (SPT) - Thí nghiệm hiện trườngFigure 1:Standard Penetration TestTools for Standard Penetration Test:
1. Standard Split Spoon Sampler
2. Drop Hammer weighing 63.5kg
3. Guiding rod
4. Drilling Rig.
5. Driving head (anvil).

 

The main purpose of the test is to provide an indication of the relative density of granular deposits, such as sands and gravels from which it is virtually impossible to obtain undisturbed samples. The great merit of the test, and the main reason for its widespread use is that it is simple and inexpensive.
The usefulness of SPT results depends on the soil type, with fine-grained sands giving the most useful results, with coarser sands and silty sands giving reasonably useful results, and clay and gravelly soils yielding results which may be very poorly representative of the true soil conditions.

Please contact us