Malcolm Drilling Company

Soil Mixing Systems

Cutter Soil Mixing • Jet Mixing • Deep Soil Mixing

Soil Mixing is a ground modification system that blends

a cementitious grout with the in situ soil to form soil

cement elements, panels or columns. Soil Mixing

methods utilize mechanical energy, in combination with

the fluidifying action of a grout slurry, to shear the soil

and create a high quality soil cement mix.

Soil Mixing has the advantage of being virtually vibra-

tionless, applicable to a wide variety of soil conditions,

highly sustainable due to its use of in situ materials,

and fully instrumented for process control and quality

assurance.

Benefits of Soil MixingMalcolm Drilling Soil Mixing Capabilities • Uses soil-cement mixed in situ, eliminating the use

of concrete or aggregate.

• Economical system to construct deep foundations and retaining walls.

• Applicable to a wide range of soils.

• Excellent method for liquefaction mitigation, settlement control,

excavation support, and seepage control.

• Can solidify contaminants in place.

Soil Mixing Applications:

• Mitigation of liquefaction potential / seismic induced

settlement / lateral spreading,

• Massive ground improvement for settlement control

or increase in bearing capacity,

• Excavation support / construction of temporary

or permanent retaining walls,

• Construction of cut-off walls for control of groundwater

and contaminants,

• In situ encapsulation of pollutants / chemical

treatment of contaminants,

• Structural support for area loads and point loads.

Soil Mixing Effectiveness by Soil Condition Cutter

Soil MixingJet Mixing

Deep Soil Mixing

Soft silts and clays ••• ••• •••

Stiff silts and clays ••• ••• •

Sands ••• ••• •••

Gravels ••• •• ••

Malcolm Drilling Company utilizes three very different

Soil Mixing techniques to provide our clients with

an optimal solution to their particular problem. Our

methods are: Cutter Soil Mixing (CSM), Jet Mixing

and Deep Soil Mixing (DSM).

Selection of the appropriate technique depends on

several factors, including the type of geotechnical

constraint, the characteristics of the soil, and the

desired end result. This ability to implement the best

suited Soil Mixing method, in combination with our

proven expertise and support, ensures that you will

get the best possible solution at a competitive price.

Cutter Soil Mixing

The CSM tool cuts vertical rectangular panels, result-

ing in fewer vertical joints when compared to multiple

shaft systems, making this system ideally suited for

constructing long soil mix structures such as retaining

walls, permeability barriers, and liquefaction mitigation

cells. This tool architecture also allows for placement

of reinforcing beams at any point along the length of

the panel, optimizing the structural design of the wall.

Case Study: 635 Elliot Avenue, Seattle, WA

Cutter Soil Mixing was selected as the method of

choice for constructing an excavation support system

to depths of 40 to 57 feet for a new office building at

635 Elliot Avenue near downtown Seattle. A cement-

bentonite mix was employed, resulting in panels ex-

ceeding 200 psi unconfined compressive strength, with

permeabilities at or below 5 x 10-6 cm/sec. The Cutter

Soil Mixing system successfully keyed into the under-

lying glacial till and effectively limited infiltration of

contaminated groundwater, offering cost and schedule

advantages over secant piles and other composite

cut-off/earth retention systems.

Benefits of Cutter Soil Mixing

• Two, vertically mounted, counter rotating heads cut and mix through

difficult soils, including stiff plastic clays, gravels and cobbles.

• Builds rectangular panels, not columns, making it ideally suited

for constructing walls.

• Instrumentation inside the cutting head monitors x, y and z coordinates of the tool in real time.

• Cutting and mixing energy generated at the point of attack.

• Has the ability to key into the underlying bedrock.

Cutter Soil Mixing, CSM, was developed from dia-

phragm wall technology and utilizes two sets of counter

rotating, vertically mounted, cutter wheels. The wheels

cut the surrounding soil, while at the same time blend-

ing the injected slurry with the in situ soil to form soil-

cement panels, 1.7 to 4 feet in width.

There are several unique aspects of CSM technology.

Most importantly, the CSM system allows for control of

the speed and rotational direction of the cutter wheels;

each wheel is controlled independently. Instrumenta-

tion housed directly inside the cutter head relays the

x, y and z coordinates of the mixing tool in real time to

a computer display inside the operator’s cab. This pro-

vides assurance of complete overlap between panels

to depths of up to 130 ft.

As a result of the hydraulic motor being housed inside

the cutter wheels themselves, energy is applied

directly at the point of attack and not at the top of the

Kelly bar. The wheels can be equipped with rock teeth

to allow cutting through difficult soils, including cobbles

up to 8 inches in diameter or bedrock with up to 5000

psi unconfined compressive strength.

635 Elliot Avenue, Seattle, Washington

Jet Mixing

Jet Mixing is a unique soil mixing system developed by

Malcolm Drilling Company that combines mechanical

paddle mixing with high pressure hydraulic energy to

shear and blend the soil in situ, creating a soil cement

mix of the highest quality. Our high energy jet mixing

system has allowed us to extend soil mixing to stiff,

highly plastic clays and weathered rock, soils not nor-

mally treated by soil mixing methods.

Jet mixing is fast and the system of choice to construct

cylindrical soil cement elements, 30 to 42 inches in

diameter, to depths of up to 65 feet. It is ideally suited

to construct soil cement piers for settlement control

and increase of bearing capacity. It is highly efficient

for constructing tangent and secant pile walls, which

can be reinforced with wide flange beams (soldier piles)

and tiebacks, as required. Because it produces a soil

cement material of the utmost quality, Jet Mixing can

routinely provide permeabilities of 1 x 10-6 cm/sec or

less for cutoff walls and groundwater barriers.

Case Study: 1 Hawthorne St, San Francisco, CA

1 Hawthorne Street, San Francisco is the site of a new

high rise condominium project. The construction plans

called for a 40 ft deep excavation through sand and

sandy clay with a water table at approximately 30 ft

below grade. Adjacent to the excavation was a circa

1910 unreinforced masonry building and a multi-story

reinforced concrete high rise. To save dewatering costs

and construction time, a composite cutoff/earth reten-

tion system was determined to be the most economical

solution. Malcolm Drilling constructed a design-build

shoring system utilizing jet mixed columns along the

two open sides of the project. There were 110 jet

mixed elements with a design unconfined compres-

sive strength of 200 psi and permeability of less than

1 x 10-6 cm/sec. 48 ft long wide flange beams were

inserted in selected jet mix columns. Post tensioned

tiebacks were utilized to support the lateral loads. The

two adjacent buildings were supported on battered jet

grout piles.

Benefits of Jet Mixing

• Combination of mechanical and hydraulic energy enables efficient installation, even in stiff, highly plastic clays.

• High energy system results in uniform, high strength soil cement blend.

• Economical system to construct walls, permeability barriers, and soil cement columns.

• Has the ability to key into the underlying bedrock.

1 Hawthorne Street, San Francisco, California

Deep Soil Mixing

Malcolm Drilling’s Deep Soil Mixing (DSM) system

utilizes mechanical mixing tools to shear the soil in

situ and mix it with a cementitious slurry pumped at

low pressure. This method has the ability to create

large soil mix columns, typically 5 to 8 feet in diameter,

to depths of up to 80 feet.

Deep Soil Mixing is a very economical system for

mass ground improvement projects. It is ideally suited

to provide settlement control and increased bearing

capacity in soft soils. Its ability to create large diame-

ter soil mix columns also make it well suited to miti-

gate the effects of liquefaction induced settlements

and lateral spreading. DSM is also the soil mixing

method of choice for in situ remediation and encapsu-

lation of contaminated soils and for the construction of

Permeable Reactive Barrier (PRB) walls.

Case Study: Market St Bridge, Santa Cruz, CA

Market Street Bridge in Santa Cruz, California required

liquefaction and lateral spreading mitigation under both

bridge abutments. The system design required 80 soil

mixed columns, three to six feet in diameter and up to

60 feet in depth, with H 10 x 42 steel beams inserted

in the center of each column to impart lateral ductility.

The construction was performed within the confines of

a residential neighborhood. The soils at the site were

primarily silty sands and silty clays with gravel lenses.

Soil mix columns were required to attain a minimum 400

psi unconfined compressive strength. The flexible tooling

allowed by this system was ideally suited to create large

and variable diameter columns, and the low pressure

grout injection was compatible with the site environmen-

tal constraints.

Benefits of Deep Soil Mixing

• Ability to construct large diameter columns.

• Very efficient and cost effective method to mix large volumes of soil.

• Effective method for settlement control, liquefaction mitigation, and remediation of contaminated soils.

Market Street Bridge, Santa Cruz, California

Date Start End Duration Size[l] K1/quantity K2/quantity K3/quantity K4/quantity K5/quantity K6/quantity Density [kg/l]

04/10/12 8:58:34 9:03:15 0:04:41 1000.00 829.52 604.64 46.40 0.00 1.419

04/10/12 9:03:15 9:08:00 0:04:45 1000.00 830.66 598.29 42.98 0.00 1.415

04/10/12 9:08:01 9:12:50 0:04:49 1000.00 830.66 599.76 43.96 0.00 1.416

04/10/12 9:12:50 9:17:36 0:04:46 1000.00 830.28 613.92 45.42 0.00 1.424

04/10/12 9:17:37 9:22:25 0:04:48 1000.00 829.14 586.08 52.75 0.00 1.412

04/10/12 9:22:26 9:27:17 0:04:51 1000.00 829.52 609.52 34.19 0.00 1.418

04/10/12 9:27:17 9:32:12 0:04:55 1000.00 831.43 608.55 51.77 0.00 1.422

04/10/12 9:32:12 9:37:10 0:04:58 1000.00 828.76 596.83 50.79 0.00 1.417

04/10/12 9:37:10 9:42:42 0:05:32 1000.00 828.76 592.43 43.96 0.00 1.412

04/10/12 9:42:43 9:48:13 0:05:30 1000.00 830.66 601.71 36.14 0.00 1.414

04/10/12 9:48:14 9:54:28 0:06:14 1000.00 829.14 599.76 40.05 0.00 1.415

04/10/12 9:54:28 9:58:39 0:04:11 1000.00 829.14 608.06 63.49 0.00 1.427

04/10/12 9:58:39 10:05:17 0:06:38 1000.00 831.04 611.48 37.12 0.00 1.419

04/10/12 10:05:17 10:09:17 0:04:00 1000.00 832.19 596.34 41.51 0.00 1.412

04/10/12 10:09:18 10:12:43 0:03:25 1000.00 828.76 602.20 44.44 0.00 1.418

04/10/12 10:12:44 10:16:08 0:03:24 1000.00 831.81 602.69 53.72 0.00 1.420

04/10/12 10:16:08 10:19:31 0:03:23 1000.00 829.90 599.76 36.63 0.00 1.414

04/10/12 10:19:32 10:22:55 0:03:23 1000.00 828.76 590.48 49.33 0.00 1.413

04/10/12 10:22:56 10:26:20 0:03:24 1000.00 829.52 604.64 40.54 0.00 1.418

04/10/12 10:26:21 10:30:12 0:03:51 1000.00 829.52 606.59 45.42 0.00 1.420

04/10/12 10:30:12 10:34:16 0:04:04 1000.00 829.90 593.90 49.82 0.00 1.415

04/10/12 10:34:16 10:38:36 0:04:20 1000.00 831.04 608.06 31.75 0.00 1.416

04/10/12 10:38:36 10:42:48 0:04:12 1000.00 828.76 601.22 57.14 0.00 1.421

04/10/12 10:42:48 10:47:12 0:04:24 1000.00 832.57 590.48 43.47 0.00 1.410

04/10/12 10:47:12 10:51:31 0:04:19 1000.00 828.76 617.34 46.89 0.00 1.427

04/10/12 10:51:31 10:55:53 0:04:22 1000.00 828.37 600.73 38.58 0.00 1.415

04/10/12 10:55:54 11:00:30 0:04:36 1000.00 830.66 604.64 55.68 0.00 1.422

04/10/12 11:00:31 11:07:24 0:06:53 1000.00 831.04 590.97 38.58 0.00 1.409

Quality Control

Every Malcolm soil mixing system is fully instrumented, monitoring grout flow rates, injection volumes, injection pressures, and penetration rate. This information is portrayed on a computer screen mounted inside the operator’s cab.

All of Malcolm Drilling’s soil mixing systems utilize

batch weight mixing grout plants with fully automated

controls. The batch plants record all grout batch

component weights, duration of mix, specific gravity

of the batch, and date and time of the batch. The ad-

vantage of this type of grout plant is the ability to add

both solid and liquid admixtures to the grout batches.

As many as 3 different solids and 4 different liquids

can be used in a grout mix, giving us the flexibility to

design grout mixes for the specific ground conditions

and engineering application.

After constructing one or more test columns and

conducting wet sampling in fresh columns and coring

in cured columns, the critical mixing parameters of pen-

etration rate, mixing speed, grout batch components,

and pumping rates are adjusted and established for the

project. Once these critical parameters are validated,

Malcolm Drilling utilizes the same QA/QC control hard-

ware and software for all three soil mixing systems.

This system monitors grout volume, grout pressure,

tool verticality, RPM, torque, crowd forces, and machine

parameters such as hydraulic energy employed. The

information is presented graphically to the operator in

real time for operational control and is recorded for Q/A

analysis. The stored data can be downloaded as a func-

tion of depth or time and is separated by down stroke

and up stroke. Included in the hard copy report are ele-

ment identification number, date, start and finish time,

and operator/rig identification.

2.00

4.00

6.00

8.00

10.00

12.00

14.00

0.00

grout FEED DoWn [1/o.2M]grout FEED up [1/o.2M]

0 46

91

137

182

228

274

319

365

-3.9 0.0 3.9

15.52

2.00

4.00

6.00

8.00

10.00

12.00

14.00

0.00

0 49

98

147

196

245

294

343

392

15.52

2.00

4.00

6.00

8.00

10.00

12.00

14.00

0.00

0 11

22

32

43

54

66

76

86

15.52

2.00

4.00

6.00

8.00

10.00

12.00

14.00

0.00

15.52

-2.9 0.0 2.9

2.00

4.00

6.00

8.00

10.00

12.00

14.00

0.00

15.52

DEviAtion v [CM]DEviAtion X [CM]DEptH progrESS [MM]

grout [1/0.2M]

SitE 635 Elliott MiXturE 1299A ForEMEn Wayne Broughton CoMponEntS 4 W/C - FACtor 1.38

proDuCtion log, CSM

JoBSitE 635 ElliotCliEnt Malcolm Drilling proJECt nuMBEr 27-443Drilling rig RG-23 i-no 75

CSM rECipE AdditivesCEMEnt 600kg BEntonitE 45kg grout DEnSity 1.41-1.42WZ 1.38 StArt 7:05:25 AMEnD 8:31:51 AM totAl tiME 01:26:26noM grout ConSuM 15.5 cbmACt grout ConSuM 19.442 cbm Cut E 117DAtE April 10, 2008WAll tHiCKnESS/DiA 0.8 mWiDtH oF Cut 2.4 m DrillED DEptH 15.52 mnoM. inClinAtion 0nuMBEr oF tESt CuBES 0 EnD DEviAtion X -1.90 cmEnD DEviAtion y -0.30 cm

MX1-1.1 CEMEnt MiX DAtA rEport

Title Req. quantity Unit Density factor K1 water 830.00 Liter 1.000 K2 cement 600.00 Kg 3.150 K3 bent 45.00 Kg 2.150 K4 mixing-time 15.00 Second

Typical production log and grout mix report.

Corporate office 92 Natoma St. Ste. #400 San Francisco, CA 94105 Tel: (415) 901-4400

ground improvement Division 3524 Breakwater Ave. Suite A -108Hayward, California 94545Tel: (510) 780-1167

San Francisco 3503 Breakwater Court Hayward, CA 94545 Tel: (510) 780-9181

los Angeles 4926 N. Azusa Canyon Road Irwindale, CA 91706 Tel: (626) 338-0035

Seattle8701 S. 192nd StreetKent, WA 98031Tel: (253) 395-3300

San Diego16885 W. Bernardo DrSuite 100San Diego, CA 92127 Tel: (858) 753-0707

las vegas2365B Renaissance Dr.Las Vegas, NV 89119Tel: (702) 650-2922

www.malcolmdrilling.com

Copyright Malcolm Drilling, Inc.

Malcolm Drilling Company

only Malcolm Drilling can provide you with a wide array of soil mixing techniques to suit your site. We can combine soil mixing with a variety of deep foundation and geotechnical construction methods to handle even the most challenging ground conditions. Our customer base is efficiently serviced through our network of regional offices, allowing Malcolm Drilling to deliver the highest quality product consistent with our position as an industry leader in soil mixing technology.