4.1 IntroductionFive tests were per

4.1 Introduction
Five tests were performed for this study using the instrumented retaining wall facility.
The test procedures, materials, and results for the instrumented retaining wall tests are presented
in the following sections.
4.2 Test Procedures and Materials
This section describes the test procedures and materials used in the instrumented
retaining wall tests. The backfill material, compaction equipment, wall preparation activities,
backfill placement and compaction procedures, cyclic testing procedures, and the instrumented
retaining wall test schedule are described.
4.2.1 Backfill
The backfill used for the instrumented retaining wall tests is Light Castle sand obtained
from a quarry in Craig County, Virginia. Light Castle sand is a clean, fine sand consisting
predominantly of subangular quartz grains. Filz and Duncan (1992) performed various
laboratory tests on Light Castle sand. For this sand, it was found that 68 percent of the material
passes the No. 40 sieve and less than 1 percent passes the No. 200 sieve. The coefficient of
uniformity and coefficient of curvature were determined to be 1.8 and 0.9, respectively.
Therefore, the sand classifies as a poorly graded sand (SP) according to the Unified Soil
Classification System. The specific gravity of solids is 2.65. The maximum and minimum
densities determined by ASTM D4253-83 and ASTM D4254-83 are 106 and 88.5 pounds per
cubic foot, respectively.
Filz and Duncan (1992) performed two instrumented retaining wall tests using Light
Castle sand, but without a compressible inclusion. The average unit weight of the compacted
17
sand was approximately 105.5 pcf, corresponding to a relative density of nearly 100 percent.
The estimated friction angle of the compacted sand was 42 degrees.
4.2.2 Compaction Equipment
For this study, two hand-operated compactors were used: a Wacker model BS60Y
(rammer compactor) and a Wacker model BPU 2240A (vibrating plate compactor). Schematic
diagrams of both compactors are shown in Figure 4.1. The rammer compactor is powered by a 4
horsepower, 2-cycle engine that drives a steel ramming shoe into contact with the soil at a
percussion rate of 10 blows per second. The operating weight of the rammer compactor is 137
pounds. The vibrating plate compactor is powered by a 5 horsepower, 4-cycle engine that drives
counter-rotating eccentric weights. These weights rotate at a frequency of about 100 Hz and are
connected by axles to a steel plate that contacts the soil. The operating weight of the vibrating
plate compactor is 275 pounds.
The rammer and vibrating plate compactor used for this study are commonly employed
for compaction in confined areas and adjacent to retaining wall structures.
These compactors are different in their mode of operation. In a study by Filz and Duncan (1992)
on the two compactors used for this research, it was found that the rammer compactor delivered
higher peak contact forces to the soil than the vibrating plate compactor. Thus, higher
compaction-induced earth pressures can be expected in backfill compacted with the rammer
compactor than in backfill compacted with the vibrating plate compactor.
4.2.3 Wall Preparation Prior to Compaction
Wall preparation consisted of lubricating the end and far walls of the backfill area and
placing TerraFlex on the instrumented wall. Lubrication of the end and far walls was
18
a) Rammer compactor
Figure 4.1: Schematic diagrams of a) Rammer Compactor and b) Vibratory Plate
Compactor (After Filz and Duncan 1992)
Eccentric
Weights
Base
Plate
Shock
Absorber
b) Vibrating plate compactor
19
performed in order to minimize the buildup of shear stresses along these walls, which could
influence the test results. Lubrication allows the facility to more closely model a 2-D case of an
infinitely long wall and infinitely wide backfill area (Filz and Duncan 1992). To lubricate the
end and far walls, a sheet of 6-mil polyethylene was taped in place on these walls. A thin layer
of wheel bearing grease was applied to the polyethylene sheet, which was then covered with a
second polyethylene sheet. The walls were lubricated for all five tests performed.
The TerraFlex was delivered in pre-cut blocks of the desired thickness. The TerraFlex
was then placed on the face of the instrumented retaining wall using GeoTech DB-784 adhesive
supplied by GeoTech Systems Corporation. The TerraFlex was applied over the full height and
length of the instrumented wall and extended 2.5 feet from the instrumented panels onto the wall
in the access ramp area.
4.2.4 Backfill Placement and Compaction
Before it was used as backfill in the instrumented retaining wall test facility, the Light
Castle sand was dried to less than 0.1 percent hydroscopic moisture and placed in a dry stockpile
area. The sand was moved from the stockpile area to the backfill area by a hopper lifted by an
overhead crane. After depositing the sand in the backfill area, it was spread by hand in loose lifts
of sufficient thickness to produce a compacted lift thickness of 6 inches. Backfill was placed
approximately 6.5 feet high against the instrumented wall for each test.
The rammer compactor delivers higher peak forces to the soil than the vibrating plate
compactor. For tests using the rammer compactor, each backfill lift was compacted with 2
passes. For tests using the vibrating plate compactor, 5 passes were used to compact each lift.
Both procedures produced relative densities near 100 percent.

ผลลัพธ์ (อังกฤษ) 2:

4.1 Introduction
Five tests were performed for this Study using the instrumented Retaining Wall facility.
The Test procedures, Materials, and results for the instrumented Retaining Wall tests are Presented
in the following Sections.
4.2 Test Procedures and Materials
This section describes the Test procedures and Materials. used in the instrumented
tests Retaining Wall. The backfill Material, Compaction Equipment, Wall Preparation activities,
backfill placement and Compaction procedures, cyclic Testing procedures, and the instrumented
Retaining Wall Test Schedule are described.
4.2.1 Backfill
The backfill used for the instrumented tests Retaining Wall Sand Castle Light is obtained
from. a quarry in Craig County, Virginia. Light Sand Castle is a Clean, Fine Sand consisting
predominantly of subangular Quartz grains. FILZ and Duncan (in 1992) performed Various
Laboratory tests on Light Sand Castle. Sand for this, it was that 68 percent of the Material Found
passes the Sieve No. 40 and less than 1 percent passes the No. 200 Sieve. The coefficient of
uniformity and coefficient of curvature were determined to be 1.8 and 0.9, respectively.
Therefore, the Sand classifies as a poorly Graded Sand (SP) according to the Unified Soil
Classification System. The specific gravity of solids is 2.65. Minimum and maximum the
ASTM D4253-83 and ASTM D4254-83 densities are determined by 106 and 88.5 pounds per
Cubic Foot, respectively.
FILZ and Duncan (one thousand nine hundred ninety-two) Two performed tests using instrumented Retaining Wall Light
Sand Castle, but Without a compressible inclusion. The average weight of the compacted UNIT
17
Sand was approximately 105.5 PCF, corresponding to a density of nearly 100 Relative percent.
The estimated Friction Angle of the compacted Sand was 42 Degrees.
4.2.2 Compaction Equipment
For this Study, Two Hand-operated Compactors. were used: a Wacker Model BS60Y
(Rammer Compactor) and a Model Wacker BPU 2240A (Vibrating Plate Compactor). Schematic
diagrams are shown in Figure 4.1 of both Compactors. Powered by the Rammer Compactor is a 4
horsepower, 2-Cycle Engine that Drives a ramming Steel Shoe Into Contact with the soil at a
rate of 10 blows per Second percussion. The operating weight of the Rammer Compactor is 137
pounds. Vibrating Plate Compactor is the Powered by a 5 horsepower, 4-Cycle Engine that Drives
Eccentric Rotating counter-Weights. Rotate these Weights at a frequency of 100 Hz and About are
Connected by a Steel Plate that Contacts axles to the soil. The operating weight of the Vibrating
Plate Compactor is 275 pounds.
The Vibrating Plate Compactor Rammer and used for this Study are commonly employed
for Compaction in confined areas and adjacent to Retaining Wall Structures.
These Compactors are different in their mode of Operation. In a Study by FILZ and Duncan (the 1,992th)
Research on the Two Compactors used for this, it was delivered Compactor Rammer Found that the
higher Peak Contact Forces to the soil than the Vibrating Plate Compactor. Thus, higher
Compaction Earth-induced pressures Can be expected in compacted backfill with the Rammer
Compactor than in compacted backfill with the Vibrating Plate Compactor.
4.2.3 Wall Preparation Prior to Compaction
Wall Preparation consisted of lubricating the End and Far Walls of the backfill Area. and
placing on the instrumented TerraFlex Wall. Lubrication of the End and Far Walls was
18
a) Rammer Compactor
Figure 4.1: Schematic diagrams of a) Rammer Compactor and B) Vibratory Plate
Compactor (After FILZ and Duncan 1992)
Eccentric
Weights
Base
Plate
Shock
Absorber
B) Vibrating Plate Compactor
19
performed in. Order to minimize the buildup of shear stresses along these Walls, which could
influence the Test results. Allows the lubrication facility to more closely a 2-D Model Case of an
infinitely long and infinitely Wall Wide Area backfill (one thousand nine hundred ninety-two FILZ and Duncan). To lubricate the
End and Far Walls, a 6-MIL Sheet of polyethylene was taped in Place these on Walls. A thin layer
of grease Bearing wheel was Applied to the polyethylene Sheet, which was then covered with a
polyethylene Second Sheet. Walls were lubricated for all the tests performed Five.
The TerraFlex was delivered in pre-Cut Blocks of the desired thickness. The TerraFlex
was then Placed on the Face of the instrumented Retaining Wall GEOTECH using DB-784 adhesive
supplied by GEOTECH Systems Corporation. Applied over the TerraFlex was the full height and
Extended Length of the instrumented Wall and 2.5 feet from the instrumented panels onto the Wall
in the Area Access ramp.
4.2.4 Backfill Placement and Compaction
Before it was used as backfill in the instrumented Retaining Wall Test. facility, the Light
Sand Castle was less than 0.1 percent to hydroscopic Dried Moisture and stockpile Placed in a Dry
Area. The Sand was moved from the stockpile to the backfill Area Area by a Hopper lifted by an
overhead Crane. After depositing the Sand backfill in the Area, it was spread by Hand in Loose lifts
of sufficient thickness to Produce a compacted lift thickness of 6 inches. Placed Backfill was
approximately 6.5 feet against the High Wall instrumented for each Test.
The Rammer Compactor Peak delivers higher Forces to the soil than the Vibrating Plate
Compactor. For tests using the Rammer Compactor, each lift was compacted backfill with 2
passes. Vibrating Plate Compactor for the tests using, 5 passes were used to Compact each lift.
Both procedures produced Relative densities near 100 percent.

ผลลัพธ์ (อังกฤษ) 3:

4.1 Introduction
Five tests were performed for this study using the instrumented retaining wall facility.
The, test procedures. Materials and results, for the instrumented retaining wall tests are presented
in the following sections.
4.2 Test Procedures. And Materials
This section describes the test procedures and materials used in the instrumented
retaining wall tests. The. Backfill, materialCompaction equipment wall preparation, activities
backfill, placement and compaction procedures cyclic testing procedures,,, And the instrumented
retaining wall test schedule are described.

4.2.1 Backfill The backfill used for the instrumented retaining. Wall tests is Light Castle sand obtained
from a quarry in, Craig County Virginia. Light Castle sand is a clean fine sand,, Consisting
.Predominantly of subangular quartz grains. Filz and Duncan (1992) performed various
laboratory tests on Light Castle, sand. For this sand it was, found that 68 percent of the material
passes the No. 40 sieve and less than 1 percent passes the No. 200, sieve. The coefficient of
uniformity and coefficient of curvature were determined to be 1.8 and 0.9 respectively.
Therefore,,The sand classifies as a poorly graded sand (SP) according to the Unified Soil
Classification System. The specific gravity. Of solids is 2.65. The maximum and minimum
densities determined by ASTM D4253-83 and ASTM D4254-83 are 106 and 88.5 pounds. Per
cubic, foot respectively.
Filz and Duncan (1992) performed two instrumented retaining wall tests using Light
Castle. Sand.But without a compressible inclusion. The average unit weight of the compacted

sand 17 was approximately, 105.5 PCF corresponding. To a relative density of nearly 100 percent.
The estimated friction angle of the compacted sand was 42 degrees.
4.2.2 Compaction. Equipment
For this study two hand-operated, compactors were used: a Wacker model BS60Y
.(rammer compactor) and a Wacker model BPU 2240A (vibrating plate compactor). Schematic
diagrams of both compactors are. Shown in Figure 4.1. The rammer compactor is powered by a 4
horsepower 2-cycle engine, that drives a steel ramming shoe. Into contact with the soil at a
percussion rate of 10 blows per second. The operating weight of the rammer compactor is. 137
pounds.The vibrating plate compactor is powered by a 5 horsepower 4-cycle engine, that drives
counter-rotating eccentric, weights. These weights rotate at a frequency of about 100 Hz and are
connected by axles to a steel plate that contacts the, soil. The operating weight of the vibrating
plate compactor is 275 pounds.
The rammer and vibrating plate compactor used for this. Study are commonly employed
.For compaction in confined areas and adjacent to retaining wall structures.
These compactors are different in their mode. Of operation. In a study by Filz and Duncan (1992)
on the two compactors used for this research it was, found that the rammer. Compactor delivered
higher peak contact forces to the soil than the vibrating plate, compactor. Thus higher
.Compaction-induced earth pressures can be expected in backfill compacted with the rammer
compactor than in backfill compacted. With the vibrating plate compactor.
4.2.3 Wall Preparation Prior to Compaction
Wall preparation consisted of lubricating. The end and far walls of the backfill area and
placing TerraFlex on the instrumented wall. Lubrication of the end and far. Walls 18 was

.A) Rammer compactor
Figure 4.1: Schematic diagrams of a) Rammer Compactor and b) Vibratory Plate
Compactor (After Filz. And Duncan 1992)


Eccentric Weights Base



Plate Shock Absorber b) Vibrating plate compactor

performed 19 in order to minimize. The buildup of shear stresses along, these walls which could
influence the test results.