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Jet Grouting Process Soilcrete ®

Contents

1 The Jet Grouting process 2 Soilcrete ® Applications 3 Properties of Soilcrete ® 4 Jet Grouting Systems 5 Constructive forms 6 Constructive sequences 7 Quality certification 8 Soilcrete® for stabilisation 9 Soilcrete® for waterproofing

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The Jet Grouting process

The Jet Grouting process or Soilcrete is known as a soil-cement stabilisation. The soil around the bore is eroded with the aid of a high-pressure jet of water or cement suspension with a nozzle output speed 100 m/sec (possibly airborne). The eroded soil is rearranged and mixed in the cement suspension. The soil-cement mix is partly ejected into the annular space between the Jet Grouting rod and the bore. Different geometric configurations of Soilcrete elements are possible. The jet erosion distance varies according to the soil type and jet fluids used, and can reach diameters of up to 5 metres.

® ®

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Soilcrete ® Applications

The Advantages of Jet Grouting - Applicable to almost all soil types - Individualised in situ treatment - Designable strength and permeability - Specific layer treatment - Inert components only - Vibration-free - Applicable in limited working spaces - Possibility of different Soilcrete elements - Maintenance-free - The safest and most direct underpinning method - Able to operate around underground installations in service - Faster than alternative methods

Navy Headquarters, Cartagena (Murcia)

Range of applications for jet-grouting techniques

Techniques

Soilcrete®/Jet Grouting Soilfrac®/Shatter Grouting

Clay

Silt

Sand

Gravel

Stone

Silicate solutions Micro-cement Cement suspension

Particle size [mmø]

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Sreen size [% weight]

Compacting Grouting

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Soilcrete ® properties

Soilcrete® acts on the land according to specification, both as stabilisation or as a hydraulic barrier structure. A combination of both is increasingly demanded. Soilcrete® single compression resistance ranges from 2 - 25 Mpa, according to cement content and the amount and type of soil remaining in the Soilcrete® mass. The Soilcrete® hydraulic barrier is obtained by selecting a suitable mix and, if necessary, adding bentonite. The type and quantity of mix of materials injected, plus the volume of soil particles remaining in the Soilcrete® mass condition the barrier properties.

Development of Soilcrete ® resistance Granular Soil

Cohesive Soil

Time (days)

Type of soil treated Resistencia a la compresión simple (RCS)(Mpa) Módulo de deformación E = ?.RCS

Clays

Silts

Clean Sand & Gravels

2-5

3-7

4 - 15

? = 300

? = 700

? = 1000

High-Speed Line. Sector Hospitalet-Can Tunis Diámetros y contenidos de cemento

Suelos de cantos pequeños Suelos gravosos Arenas Limosas

Facilidad para disgregar (Grandes Diámetros)

Tipo de suelo tratado Soilcrete® S Soilcrete® D Soilcrete® T Supert Jet

D (m) 0,45 ÷ 0,80 0,60 ÷ 2,00 1,00 ÷ 2,50 2,00 ÷ 5,00

C (Kg/m) 250 ÷ 400 500 ÷ 1400 800 ÷ 1500 1000 ÷ 8000

Arenas Limosas sueltas Turba y limos orgánicos Arenas limosas densas Arenas Arcillosas densas

Los valores bajos de diámetro corresponden normalmente a los suelos muy cohesivos o muy densos, y los altos a los granulares flojos.

Limos de baja plasticidad Arenas Arcillosas densas Arcillas de baja plasticidad Limos de alta plasticidad Arcillas de baja plasticidad (duras)

Dificultad para disgregarr (Pequeños Diámetros)

Arcillas de alta plasticidad

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Jet Grouting® Systems

Single rod

There are three traditional Jet Grouting systems. Choice of the most suitable system depends on the soil to be treated, and the application and Soilcrete properties required for the application. Any system can however be used for almost all applications if the design and implementation are consistent with the system chosen. Monofluid (Soilcrete® S) The cement grout is pumped by the rods, emerging at high speed (approx. 200m/sec) from the horizontal monitor nozzle. This energy causes the soil to erode, break down, mix and displace, and this is the system recommended for general improvement treatments, waterproofing and anchor bulbs. Double fluid (Soilcrete® D)

Hydraulic Monitor

Grouting

Single fluid Double rod

Water

Two-phase internal rodding is used to separate the water supply and cement grout into two vertically displaced nozzles. The land breakdown is aided by high-water pressure through the top nozzle, while the cement grout is injected through the lower nozzle. The double system is more effective that the monofluid procedure for cohesive soils, is widely used, and especially recommended for underpinning. Triple fluid (Soilcrete® T) Grout, air and water are pumped along different lines to the monitor. Air at high speed, and water, form the erosive medium. The grout emerges at a lower speed from a separate nozzle under that for the erosion Jet. This separates the erosion process from the grouting and obtains better quality Soilcrete. It is used most efficiently in treatments for general improvement and waterproofing. Super Jet Grouting The base of this system is a double fluid procedure (air+grouting), but with a highlysophisticated monitor, especially designed to govern and precisely focus the energy from the Double grouted matter. The grouting is used to erode and mix with the soil. The air surrounds the rod grouting Jet to enhance erosion efficacy. With low-speed rotation and ascent, large soilcrete column diameters are obtained. Efficient for massive treatments, slabs and bottom caps.

Grouting Grouting

Double fluid

Triple rod

Air Water Air

Grouting

Triple fluid

Air Grouting Air

Super Jet

A hydraulic barrier using jet grouting columns in the screen wall extrados, with insufficient imbedding. Home construction, Peñiscola, Castellón.

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Constructive forms

The basic geometric form of the Soilcrete element is created by the movements of the bore bars: 1. Rodding rises, without rotation, to give panels if several Jet nozzles are used, and multiple panels can be made. 2. Segments are created by rising and rotating on its axis. 3. Complete columns are created by rising and rotating.

Simgle

Duoble

Line 8 Extension, Madrid Metro: Mar de Cristal-Nuevos Ministerios

Column A. Quarter B. Half C. Complete

Panel

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Constructive Sequences

Soilcrete installations comprise storage containers, silos and a mixing and pumping unit. Several high-pressure hoses and control cables connect the pumping unit with the Soilcrete boring equipment at the work site. The equipment mast varies between 2 and 35 metres. Bore points are normally located in small channels fitted with sludge pumps, from where excess material, a mix of water-soil-cement, is pumped for elimination later.ial de exceso, una mezcla de agua-suelo-cemento, es bombeada para posterior eliminación.

The process for building a Super Jet column Insertion of tooling into bore Injection of cement grouting at high speed with air Termination of the SuperJet Column

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Quality certification

Monitoring the process Up to 12 parameters in Soilcrete construction are registered and used by the technician in charge of supervision and control.

Quality certification Certification and quality control are critical components of a Jet Grouting programme, to ensure that the soil conditions are in line with the criteria for the calculation, and the design parameters are met or exceeded in the whole project. Quality certification begins with a field test to confirm geometries, and the characteristic quality and strength of the Soilcrete product. Fresh, hardened samples are taken to confirm that the RCS is reached satisfactorily. Compilation of all the Jet Grouting parameters means that they are available, with real-time observation. Quality control In addition to controls on each Soilcrete element, the measurements and control specified in each project may be required, along with structural monitoring or permeability trials. Controlled implementation with Soilcrete creates a reject or resurgent material during the erosion process. Its volume can be predicted from the volumes injected, and is typically in the range of 40 - 60% of the volume of Soilcrete. The reject has cement content, and gains strength over time so that, after 12 hours, it can be handled like a firm clay, and is commonly used as construction fill.

1 Quality control inspection items Boring Location, angle, depth, procedures for maintaining repeatability Preparation of the grouting mix according to the dosage consistency required, and checks on its physical and chemical properties Confirmation of the bore parameters (ascent, speed and rotation) and grouting parameters (pressure and flow of all components) According to implementation of each element constructed, with its register of parameters. Controls on construction time, and correlation with sampling Recovery of representative samples for trials Apparatus for measuring the diameter of Jet Grouting columns between 1 and 4m 2 Results of the SupertJetGrouting field test

Mixing

Grouting

Documentation

Sampling and trials ensayos 3

1. Registration of the main performance parameters are stored electronically. 2. Operating panel and extraction, the M4 unit register. 3. Sample specimens of Soilcrete elements.

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Soilcrete ® for stabilisation

Underpinning

Underpinning by low-deformation gravity walls, sometimes functioning simultaneously as a hydraulic barrier.

Restoration of foundations

Historic buildings may be at risk from settlement. Soilcrete provides sure foundations, with maximum structural protection.

Consolidation of foundations using Jet Grouting, San Millán de la Cogolla Temple (La Rioja)

Reinforcement of foundations

Changes of use, or alterations to buildings usually require enhanced foundations or changes to them. Soilcrete provides an economical and flexible solution for this task.

Deep foundations

Soilcrete is used for new foundations which require special care because of the proximity of historic structures with very sensitive foundations.

Tunnel protection

Tunnel protection is mainly used in loose soils under or near structures requiring protection. The aim is sometimes to limit the ingress of water during tunnel excavation.

Horizontal Soilcrete

Horizontal Soilcrete columns protect tunnel penetration in loose soil formations, and are built from the tunnel face, horizontally or on a slight slope.

Etch shaft support

If a shaft has to be built without vibrations, and/or it penetrates below the water level, drying Soilcrete columns are installed.

Thrust reduction

The performance of structures exposed to land thrust, e.g. historic walls, bridge abutments, avalanche galleries, slopes or port walls, can be enhanced by the addition of and/or connection to a Soilcrete body.

Pile reinforcement

In case of insufficient embedding or to avoid excessive bore depths, a pile sinking load can be increased, on the shaft, at the end, or both.

Jet Grouting etch shaft, Luarca (Asturias)

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Soilcrete ® for waterproofing

Use of Soilcrete hydraulic barriers and caps to reduce permeability allows for deep excavations without having to lower the water level using large depletion systems, with their consequence risks. Soilcrete uses non-environmentally-pollutant mineral binders. Panel barrier Soilcrete hydraulic panel barriers are used under roads and buildings to carry collectors and divide excavations and enclosures. Depending on seal requirements, they are built of single or multiple panels. Column barrier Where deformation is greater than anticipated, or there is risk of fissuring or a high seal requirement, Soilcrete column barriers can be built. Dam waterproofing Soilcrete can be used to repair dam cores or enlarge or deepen the hydraulic barrier.

Underground Bilbao: Las Arenas-Lamiako

Bottom slabs or caps Soilcrete bottom slabs or caps are built by overlapping column components at a give depth and thickness. The caps can be connected to any vertical seal system. Arched slabs For excavations of reduced widths, or etch shafts, Soilcrete caps are used to prevent hydrostatic pressure, reducing the slab depth normally needed to bear those pressures. Seal layer A layer of Soilcrete protects against the water level under buildings from construction activities and old toxic deposits.

Joint seal To seal joints between sheet piles or other construction procedures on the site.

Water output Hydraulic barriers are normally used to control water flow temporarily. To reinstate flow, the Soilcrete process can be used to wash the cementing material from certain sections.

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Miguel Yuste, nº 45 Bis E28037 Madrid Tel.: 914 237 561 Fax: 914 237 501 Web: www.kellerterra.com Mail general: [email protected] com

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