TECHNICAL FIELD
The present disclosure relates to the field of civil engineering. Particularly, but not exclusively,
the present disclosure relates to geotechnical engineering. Further, embodiments of the present
5 disclosure, discloses a device for measurement of hammer energy in a standard penetration test
(SPT) of soil and a system thereof.
BACKGROUND OF THE DISCLOSURE
A standard penetration test (SPT) is a commonly used test for geotechnical investigations to
10 characterize in-situ soil strength for foundation design of various structures. The standard
penetration test advantageously allows for retrieval of soil sample after the SPT measurement
is performed. The SPT test involves dropping a free-falling mass (hammer) from a predefined
height onto the anvil, which is connected to the drill rod. The drill rod has a split spoon sampler
at the bottom end, which penetrates the soil in a borehole after the hammer strikes the anvil.
15 The number of blows required to penetrate a predefined depth of soil is counted with a periodic
penetration interval, and the number of blows required for a final predefined depth of
penetration is reported as the SPT N-value (the result of the SPT test). SPT measurement is
utilized to correlate the N-value with various soil parameters such as soil density, consistency,
friction angle, undrained shear strength, Young's modulus, shear wave velocity, shear modulus,
20 damping, settlement of shallow and deep foundations in the sand, bearing capacity values, etc.
The N-value is also used to assess the index of resistance to soil liquefaction (soil liquefaction
occurs when a saturated or partially saturated soil substantially loses strength and stiffness in
response to cyclic stress, such as that developed during an earthquake).
25 SPT is subject to many variables that affect the N-value. These variables include drill rod length
and type, size of anvil, operator's efficiency, use of liner in a borehole, and type of hammer
(shape and size of hammer, the lifting, and releasing mechanism). Such variables are numerous
and resulting data may not be standardized and the existing techniques may not account for
such variables.
30
The present disclosure is directed to overcome one or more limitations stated above. The
background section of the present disclosure should not be considered as a limitation of the
present disclosure.
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3
SUMMARY OF THE DISCLOSURE
One or more shortcomings of the conventional device and system are overcome by a device
and a system as claimed and additional advantages are provided through the provision of such
5 device and system as claimed in the present disclosure.
Additional features and advantages are realized through the material of the present disclosure.
Other embodiments and aspects of the disclosure are described in detail herein and are
considered a part of the claimed disclosure.
10
In one non-limiting embodiment of the disclosure, a device for measurement of hammer energy
in a standard penetration test of soil is disclosed. The device includes a sampling module
defined with a first end and a second end. The first end is connected to a cutting shoe and
configured to penetrate the soil. Further, the device includes a first instrument rod joined at the
15 second end of the sampling module. The first instrument rod is positioned below ground level.
Furthermore, the device includes a plurality of first sensors positioned along a length of the
first instrument rod and proximal to the sampling module. The plurality of first sensors are
configured to measure acceleration of the first instrument rod and force transferred to the first
instrument rod. Additionally, the device includes a data processing unit communicatively
20 coupled to the plurality of first sensors . The data processing unit is configured to receive the
signals corresponding to acceleration and force from the plurality of sensors and determine
hammer energy.
In an embodiment of the disclosure, the sampling module is a split spoon sampler and is
25 substantially cylindrical and hollow for collecting soil sample.
In an embodiment of the disclosure, the device includes a housing coupled to the first
instrument rod and the plurality of first sensors are positioned within the housing.
30 In an embodiment of the disclosure, the plurality of first sensors includes at least one
accelerometer configured to measure acceleration of the first instrument rod and at least one
load sensor configured to measure force transferred to the first instrument rod.
In one non-limiting embodiment of the disclosure, a system for measurement of hammer
35 energy in a standard penetration test (SPT) of soil is disclosed. The system includes a sampling
module defined with a first end and a second end. The first end is connected to a cutting shoe
4
which is configured to penetrate the soil. The system also includes a first instrument rod defined
with an upper end and a lower end. The lower end of the first instrument rod is coupled to the
second end of the sampling module. The first instrument rod is positioned below ground level
and configured to measure acceleration signals and force signals from a plurality of first sensors
5 positioned along the first instrument rod and proximal to the sampling module. Further, the
system includes a first guide rod defined with a primary end and a secondary end. The primary
end of the first guide rod is coupled to the lower end of the first instrument rod. Furthermore,
the systems includes a second instrument rod defined with a leading end and a trailing end. The
leading end of the second instrument rod is coupled to the secondary end of the first guide rod.
10 The second instrument rod is positioned above the ground level and is configured to measure
acceleration signals and force signals from a plurality of second sensors positioned along the
second instrument rod. Additionally, the system includes a data processing unit configured to
receive the acceleration signals and force signals from the plurality of first sensors and second
sensors and determine the hammer energy.
15
In an embodiment of the disclosure, the system includes a first housing coupled to the first
instrument rod and configured to house the plurality of first sensors.
In an embodiment of the disclosure, the system includes a second housing coupled to the
20 second instrument rod and configured to house the plurality of second sensors.
In an embodiment of the disclosure, the sampling module is a split spoon sampler and is
substantially cylindrical and hollow for collecting soil sample.
25 In an embodiment of the disclosure, the plurality of first sensors includes at least one
accelerometer configured to measure acceleration of the first instrument rod and at least one
load sensor configured to measure force transferred to the first instrument rod.
In an embodiment of the disclosure, the plurality of second sensors includes at least one
30 accelerometer configured to measure acceleration of the second instrument rod and at least one
load sensor configured to measure force transferred to the second instrument rod.
It is to be understood that the aspects and embodiments of the disclosure described above may
be used in any combination with each other. Several of the aspects and embodiments may be
35 combined together to form a further embodiment of the disclosure.

We claim:
1. A device (100) for measurement of hammer energy in a standard penetration test (SPT)
of soil, the device (100) comprising:
5 a sampling module (10) defined with a first end (11a) and a second end (11b),
wherein the first end (11a) is connected to a cutting shoe (10a), configured to penetrate
the soil;
a first instrument rod (20a) joined at the second end (11b) of the sampling
module (10), the first instrument rod (20a) is positioned below ground level;
10 a plurality of first sensors (30a, 30b) positioned along a length of the first
instrument rod (20a) and proximal to the sampling module (10), the plurality of first
sensors (30a,30b) are configured to measure acceleration of the first instrument rod
(20a) and force transferred to the first instrument rod (20a);
a data processing unit (70) communicatively coupled to the plurality of first
15 sensors (30a, 30b), the data processing unit (70) is configured to receive the signals
corresponding to acceleration and force from the plurality of sensors (30a, 30b) and
determine hammer energy.
2. The device (100) as claimed in claim 1, wherein the sampling module (10) is a split
20 spoon sampler and is substantially cylindrical and hollow for collecting soil samples.
3. The device (100) as claimed in claim 1 comprises a first housing (40a) coupled to the
first instrument rod (20a) and the plurality of first sensors (30a, 30b) are positioned
within the first housing (40a).
25
4. The device (100) as claimed in claim 1, wherein the plurality of first sensors (30a, 30b)
comprises at least one accelerometer (30a) configured to measure acceleration of the
first instrument rod (20a) and at least one load sensor (30b) configured to measure force
transferred to the first instrument rod (20a).
30
5. A system (200) for measurement of hammer energy in a standard penetration test (SPT)
of soil, the system (200) comprising:
a sampling module (10) defined with a first end (11a) and a second end (11b),
wherein the first end (11a) is connected to a cutting shoe (10a) which is configured to
35 penetrate the soil;
18
a first instrument rod (20a) defined with an upper end (12b) and a lower end
(12b), wherein the lower end (12a) of the first instrument rod (20a) is coupled to the
second end (11b) of the sampling module (10), the first instrument rod (20a) is
positioned below ground level and configured to measure acceleration signals and force
5 signals from a plurality of first sensors (30a, 30b) positioned along the first instrument
rod (20a) and proximal to the sampling module (10);
a first guide rod (50) defined with a primary end (14a) and a secondary end
(14b), wherein the primary end (14a) of the first guide rod (50) is coupled to the lower
end (12b) of the first instrument rod (20a);
10 a second instrument rod (20b) defined with a leading end (13a) and a trailing
end (13b), wherein the leading end (13a) of the second instrument rod (20b) is coupled
to the secondary end (14b) of the first guide rod (50), the second instrument rod (20b)
is positioned above the ground level and is configured to measure acceleration signals
and force signals from a plurality of second sensors (30c, 30d) positioned along the
15 second instrument rod (20b); and
a data processing unit (70) configured to receive the acceleration signals and
force signals from the plurality of first sensors (30a, 30b) and second sensors (30c, 30d)
and determine the hammer energy.
20 6. The system (200) as claimed in claim 5 comprises a first housing (40a) coupled to the
first instrument rod (20a) and configured to house the plurality of first sensors (30a,
30b).
7. The system (200) as claimed in claim 5 comprises a second housing (40b) coupled to
25 the second instrument rod (20b) and configured to house the plurality of second sensors
(30c, 30d).
8. The system (200) as claimed in claim 5, wherein the sampling module (10) is a split
spoon sampler and is substantially cylindrical and hollow for collecting soil samples.
30
9. The system (200) as claimed in claim 5, wherein the plurality of first sensors (30a, 30b)
comprises at least one accelerometer (30a) configured to measure acceleration of the
first instrument rod (20a) and at least one load sensor (30b) configured to measure force
transferred to the first instrument rod (20a).
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19
10. The system (200) as claimed in claim 5, wherein the plurality of second sensors (30c,
30d) comprises at least one accelerometer (30c) configured to measure acceleration of
the second instrument rod (20b) and at least one load sensor (30d) configured to
measure force transferred to the second instrument rod (20b)