Application of geosynthetic materials to strengthen weak soil

Igor Meshcherin

INTRODUCTION

SOFT SOIL IS A SIGNIFICANT PROBLEM IN RUSSIA

ALMOST 60% OF THE TERRITORY HAS A PROBLEM OF SOFT SOIL PRESENCE

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SOFT SOIL

SOFT SOIL INCLUDES COHESIVE SOILS WITHSHEAR STRENGTH UNDER NATURAL OCCURRENCECONDITIONS WHEN TESTED BY A ROTARY CUT DEVICELESS THAN 0.075 MPA, RESISTIVITY TO STATICSENSING CONE WITH AN ANGLE AT THE TOP OFΑ=30° LESS THAN 0.02 MPA OR SEDIMENT MODULEAT A LOAD OF 0.25 MPA MORE THAN 50 MM/M(DEFORMATION MODULE BELOW 5 MPA).

IN THE ABSENCE OF TEST DATA TO WEAK SOILSARE INCLUDED: PEAT AND BY PEATY SOILS, SILTS,SAPROPELS, CLAY SOILS WITH A CONSISTENCY RATIOGREATER THAN 0.5, YOLDIAN CLAYS, WET SOILS, SALTMARSHES.

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CONSTRUCTION OF EMBANKMENTS

ON A WEAK GROUND

PRINCIPLES OF CONSTRUCTION OF EMBANKMENTS ON WEAK GROUND

REMOVE SOFT SOIL AND REPLACE IT OR USE RAMPS

THE APPLIANCE OF SOFT SOIL AS A BASE, WITH ACTIONS ENSURING STABILITY OF

THE BASE AND ACCELERATION OF ITS SETTLEMENT

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MEASURES TO IMPROVE STABILITY

1. CONSTRUCTION OF LOG PLANKROAD.

2. USE OF GEOMATERIALS.3. CONSTRUCTION ON PILES.4. SLOW EMBANKMENT FILLING.5. USE OF BALANCE WEIGHT

(KENTLEDGES).6. REDUCTION OF THE LOAD ON

THE FILLING DAM.7. CONSTRUCTION OF THE LOW

WEIGHT FILLING DAMS.

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CONSTRUCTION OF THE ROADS FOR US ARMY

HISTORICAL REFERENCE

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1998 - CONSTRUCTION OF THE ROAD KHANTY-MANSIYSK-NYAGAN

FIRST PROJECT DONE

HISTORICAL REFERENCE

all rights reserved / www.prestorus.com PRESTORUS, LLC7

TRADITIONAL THREE-DIMENSIONAL

POLYMER CELLS

THREE-DIMENSIONAL (3D)POLYMER CELLS ARE HONEYCOMBSTRUCTURES PRODUCED BY THEMETHOD OF WELDING POLYMERSTRIPS (TAPES) WITH HIGH-STRENGTH ULTRASONIC WELDINGIN STAGGERED ORDER. STRIPS, AS ARULE, ARE MADE OF HIGH-DENSITYPOLYETHYLENE (HDPE) WITH NOADDITIONAL REINFORCEMENT.

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DYNAMIC LOADS FROM MOVING VEHICLES

STRUCTURAL LAYERS OF ROADS (BASE,ROAD PAVEMENT) ARE SUBJECT TOCONSTANT DYNAMIC LOADS FROMMOVING VEHICLES. THEREFORE, LOADBEARING CAPACITY OF THE ROADSHOULD BE CONSTANTLY MAINTAINED.IT IS ACHIEVED DUE TO THE THICKNESSOF STRUCTURAL LAYERS.

TRADITIONALLY, IN THE CONSTRUCTIONOF ROADS, THE REQUIRED VALUE OFTHIS INDICATOR IS ACHIEVED DUE TOTHE THICKNESS OF THE STRUCTURALLAYERS, DEPENDING ON THEFOUNDATION SOILS, AND ALSO ON THEROAD CATEGORY.

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AN ALTERNATIVE WAY TO INCREASE THE LOAD-CARRYING CAPACITY OF STRUCTURAL LAYERS OF HIGHWAYS IS THE USE THREE-DIMENSIONAL (3D) GEOCELLS. IT HAS BEEN PROVED THAT GEOCELLS CONTRIBUTE TO INCREASING THE LOAD-

BEARING CAPACITY OF BASES AND ROAD CLOTHES. ALSO, THEY MAKE IT POSSIBLE TO REDUCE THICKNESS OF STRUCTURAL LAYERS AND USE A CHEAPER LOCAL FILLER MATERIAL INSTEAD OF EXPENSIVE AND HIGH QUALITY AGGREGATE MADE OF

INERT MATERIALS. THIS ALLOWS YOU TO SAVE UP TO 20% OF THE PROJECT COST.

PLASTIC DEFORMATION OF TRADITIONAL GEOCELLS UNDER INFLUENCE OF LOAD AND ELEVATED TEMPERATURES:

DISADVANTAGES OF

TRADITIONAL 3D POLYMER CELLS

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DISADVANTAGES OF

TRADITIONAL 3D POLYMER CELLS

STRENGTH OF TRADITIONAL 3D POLYMER CELLS IS USUALLY DETERMINEDBY THE FOLLOWING:

PRESENCE OF SECONDARY POLYETHYLENE IN THE COMPOSITION OF RAW MATERIALS(THE HIGHER THE SHARE OF SECONDARY RAW MATERIALS, THE LOWER THE STRENGTHAND SERVICE LIFE);

STRIP THICKNESS (ACCORDING TO INDUSTRY STANDARDS, THE OPTIMUM THICKNESSSHOULD BE AT LEAST 1.5 MM).

THE MAIN DRAWBACK OF TRADITIONAL THREE-DIMENSIONAL POLYMER CELLS IS HIGH ELASTICITY OF THE MATERIAL (UP TO 250%).

TRADITIONAL THREE-DIMENSIONAL POLYMER CELLS CAN NOT MAINTAIN GEOMETRY STABILITY OF THE CELLS UNDER LOADS.

RESULT:

FILLER MATERIAL OVER-CONSUMPTION;

STRUCTURE DEFORMATIONS ALREADY A YEAR AFTER LAYING. DEFORMATION OF A SLOPE REINFORCED WITH

TRADITIONAL THREE-DIMENSIONAL POLYMER CELLS

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MOVIE

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GEOCORD® – INNOVATIVE APPROACH

TODAY, OUR EFFORTS ARE AIMED AT DEVELOPING INNOVATIVE SOLUTIONS

IN THE FIELD OF GEOSYNTHETICS

WE STRIVE TO CREATE NEW MATERIALS AND IMPROVE THE PRODUCTS ALREADY AVAILABLE IN OUR ARSENAL. THE GOALS OF THEDEVELOPMENT ARE REDUCTION OF PRICES NOT AT EXPENSE OF QUALITY, INCREASE IN MANUFACTURABILITY, RELIABILITY, EFFICIENCY,LONGEVITY OF MATERIALS, INSTALLATION SIMPLIFICATION.

AT THIS PRESENTATION WE ARE PLEASED TO PRESENT TO YOU THE RESULTS OF OUR LATEST DEVELOPMENTS AND TO SHARE WITH YOUTHE ADVANTAGES OF THE MATERIAL, WHICH WE ARE SURE WILL HELP YOU TO OPTIMIZE TECHNICAL SOLUTIONS, AS WELL AS TO SOLVENUMBER OF PROBLEMS.

APPLICATION:

REINFORCEMENT OF ROADBEDS, EMBANKMENTS, PLATFORMS

REINFORCEMENT OF WEAK BASES AND STRUCTURAL LAYERS OF ROADS, RAILWAYS

ARRANGEMENT OF DURABLE TECHNOLOGICAL DRIVEWAYS, SERVICE DRIVES,

ARRANGEMENT OF PARKING LOTS FOR MASSIVE CONSTRUCTION EQUIPMENT

INSTALLATION OF FOUNDATIONS FOR PAVERS, PAVING SLABS LAYING

INSTALLATION OF SEISMICALLY RESISTANT RETAINING WALLS

EROSION CONTROL OF COMPLEX SLOPES

PROTECTION OF EMBANKMENTS, DAMS

CONSTRUCTION OF SURFACE WATER DISPOSAL STRUCTURES

INNOVATIVE PRODUCT:

GEOCORD®

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INNOVATIVE REINFORCED

GEOCELL GEOCORD®

UNLIKE TRADITIONAL THREE-DIMENSIONAL POLYMER CELLS

GEOCORD® STRIPES ARE STRENGTHENED WITH EXTRA HIGH REINFORCING FIBERS LONGITUDINALLY

HIGH-QUALITY HIGHT STRENGHT COMPOSITE

MATERIAL

EXTRA HIGH REINFORCING FIBERS

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UNIQUE PROPERTIES OF GEOCORD®

THE INNOVATIVE PATENTED TECHNOLOGY OF GEOCORD® MANUFACTURING CONSISTS OF INCLUSION OF ULTRA-STRONG REINFORCING FIBERS IN THE IN THE POLYETHYLENE TAPE WHAT PREVENTS PLASTIC DEFORMATION OF THE CELLS. THUS, GEOCORD® DOES NOT STRETCH

UNDER THE INFLUENCE OF CONSTANT LOADS AND ELEVATED TEMPERATURES, PRESERVING ITS GEOMETRIC DIMENSIONS AND SHAPE

ТRADITIONAL GEOCELL INNOVATIVE GEOCELL GEOCORD®, REINFORCED WITH HIGH-STRENGTH FIBERS

THE MAIN PROPERTY OF GEOCORD® IS THE INCREASED RESISTANCE TO PLASTIC DEFORMATION. CONSTRUCTIONS WITH GEOCORD® CAN MAINTAINGIVEN INDICATOR OF BEARING CAPACITY FOR A NUMBER OF YEARS, WHICH CONTRIBUTES TO INCREASE IN THE ROAD LIFE TIME.

THIS UNIQUE PROPERTY MAKES IT POSSIBLE TO APPLY GEOCORD® IN CONSTRUCTIVE LAYERS OF HIGHWAYS AND ACHIEVE SAVINGS OF UP TO 20%OF THE PROJECT COST BY REDUCING THICKNESS OF LAYERS AND USING A CHEAPER AGGREGATE INSTEAD OF EXPENSIVE HIGH-QUALITY INERTMATERIALS. • BY 10% INCREASE OF LOAD-CARRYING

CAPACITY OF BASE SOILS

• BY 55% INCREASE OF ROAD LIFE TIME

• UP TO 20% ECONOMY ON THE PROJECT

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STABILITY TO DEFORMATION UNDER TEMPERATURE CHANGES

TRADITIONAL 3D CELLS WHILE HEATING EXPAND TO THE EXTENT THAT THEY LOSE LIMITING PROPERTIES, AND CONTRACTUPON COOLING (INERTIAL EFFECT), THUS CREATING A PRESSURE THAT JEOPARDIZES CELLS INTEGRITY

AMBIENT TEMPERATURE (NOMINAL CELL

SIZE)

Т= 75 оС (CELLS EXPAND)

Т= -60 оС(CELLS CONTRACT)

TRADITIONAL GEOCELLS ARE SUBJECT TO

DEFORMATION AT TEMPERATURE DIFFERENCES

DUE TO HIGH-STRENGTH REINFORCING THREADS, GEOCORD® HAS A VERY HIGH LONG-TERM RESISTANCE TO TEMPERATURE CHANGES.GEOCORD® RETAINS ITS LIMITING PROPERTIES AT HIGH AND LOW TEMPERATURES, AND THERE IS NO DANGER OF RUPTURE ORDESTRUCTION OF THE GEOCELLS WALLS

Т= -60 оС AMBIENT TEMPERATURE(NOMINAL CELL SIZE)

Т= 75 оС

UNIQUE PROPERTIES OF GEOCORD®

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GEOCORD® ADVANTAGES

ECONOMIC BENEFITS:

• UP TO 15% SAVINGS BY REDUCING TAPE THICKNESS WITH NO DAMAGE TO PHYSICAL

AND MECHANICAL PROPERTIES

• UP TO 20% SAVINGS BY REPLACING CRUSHED STONE ON SAND INFILL

TECHNICAL BENEFITS:

• UP TO 50% INCREASE OF STRENGTH PROPERTIES

• UP TO 75 YEARS INCREASED PRODUCT LIFE CYCLE

• INCREASED RESISTANCE TO LONG-TERM DYNAMIC AND STATIC LOADS

• RESISTANCE TO DEFORMATION UNDER MULTIPLE TEMPERATURE CHANGES

• 100% RESISTANCE TO REPEATED FREEZING AND THAWING

• 100% RESISTANCE TO UV-OXIDATION

• 98% RESISTANCE TO CYCLIC LOADS

FUNCTIONAL BENEFITS:

• REDUCTION OF VERTICAL STRESS ON SUBGRADE LAYER BY 67%

• REDUCTION OF ROAD SURFACE THICKNESS BY 22%

• INCREASE OF LOAD-BEARING CAPACITY BY 10%

• INCREASE OF RESISTANCE TO LOADS BY 35%

• REDUCTION OF PLASTIC DEFORMATION BY 35%

• INCREASE OF SERVICE LIFE OF CONSTRUCTIONS BY 55%

LIFETIME 8 YEARS LIFETIME 12 YEARS AND OVER

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TEXTURING AND PERFORATION

60%

65%

70%

75%

80%

85%

90%

95%

100%

SMOOTH

TEXTURE

PERFORATED

SAND-GRAVEL MIXTURE SAND GRAVEL

ТHE TEXTURING OF THE POLYMER STRIPS ALLOWS TO INCREASE THE FRICTIONBETWEEN THE WALL OF THE GEOCELL AND INERT AGGREGATE. IT PROVIDES THEBEST RESISTANCE OF THE COMPOSITE LAYER TO DEFORMATIONS WHENAPPLYING THE GEOСORD® GEOCELL IN THE CONSTRUCTION OF EMBANKMENTS.IT REDUCES THE LOAD ON THE UNDERLYING BASE.

PERFORATION IMPROVES LATERAL DRAINAGE FROM THE COMPOSITE LAYER.

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CONSTRUCTION OF ROADS

ON SOFT GROUNDS

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FUNCTIONAL PRINCIPLE:

VERTICAL LOADS REDISTRIBUTION

FLEXIBLE SLABLOAD REDISTRIBUTES ONTO THE NEIGHBORING CELLS, REDUCING STRESS ON THE UNDERLYING BASEMENT AND

CREATING THE “FLEXIBLE SLAB” EFFECT

WITHOUT GEOCORD® WITH GEOCORD® APPLIANCE

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DESCRIPTION OF THE PAVEMENT LAYER

FOR THE SEPARATION OF LAYERS MADE OF BULK MATERIALS AND GRANULAR SOILS, IT IS RECOMMENDED TO USE A LAYEROF NON-WOVEN GEOTEXTILE WITH A DENSITY OF AT LEAST 300 G/M2.

TO FILL THE GEOCELL IT IS RECOMMENDED TO USE GRANULAR SOIL WITH A MAXIMUM PARTICLE SIZE UP TO 50 MM. THEQUANTITY OF SILT AND CLAY PARTICLES SHOULD NOT BE MORE THAN 10%.

IN ORDER TO AVOID DEFORMATIONS UNDER THE LOAD, ITS NECESSARY TO PUT PROTECTIVE LAYER MORE THAN 50CMABOVE THE GEOСORD® GEOCELL LAYER. 21

IMPLEMENTED PROJECT

WE APPLIED GEOСORD® TYPE С 200/344, WHICH WAS LAIDOVER SEPARATION LAYER MADE OF NON-WOVEN GEOTEXTILE.

THE GEOCELL IS FILLED WITH LOCAL SAND AND GRAVEL.

DESIGN LOAD FROM THE WHEEL– 55 KN

THE ESTIMATED HEIGHT OF THE MOUND WITH APPLIANCE OFGEOCELLS – 80 CM.

THE HEIGHT OF THE EMBANKMENT WITH APPLIANCE OFGEOСORD® – 30 CM .

REDUCED EMBANKMENT HEIGHT UP TO 2,7 TIMES.

PIPELINE ROAD ON YAMAL (RUSSIA, 2017)

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IMPLEMENTED PROJECT

UNDERGROUND MINE (RUSSIA, 2018)

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MOVIE

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•GEOSTEP – NEW SOLUTION FOR THE SLOPES STABILITY

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90 ̊

THE FILLER MATERIAL IS SECURELY HELD IN THE GEOSTEP® CELLS

THIS DISADVANTAGE HAS BEEN COMPLETELYELIMINATED WITH IMPROVED DESIGN OFGEOSTEP®.

THE WALLS OF GEOSTEP® CELLS AREPERPENDICULAR TO THE HORIZON, SO THEFILLER MATERIAL IS NOT SUBJECT TOPRECIPITATION FROM THE CELLS, ANDTHEREFORE DO NOT NEED TO CARRY OUTAN ANNUAL SET OF CORRECTION WORKS.

YOU CAN SAVE UP TO 10%ANNUALLY ON THEOBJECT MAINTENANCE

OPTIMAL SOLUTION

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GEOSTEP® IS A MODERN AND MORE EFFICIENT VOLUMETRIC GEOCELL FOR STABILIZATION AND ANTI-EROSION PROTECTION OF SLOPES. IT IS A POLYMER SHEET WITH LONGITUDINAL SECTIONS ARRANGED IN ASTAGGERED ORDER (FIG.1). TO FACILITATE TRANSPORT AND STORAGE, GEOSTEP® IS DELIVERED IN ROLLS(FIG.2). WHEN THE SHEET IS STRETCHED ON THE SLOPE, A VOLUME CELLULAR STRUCTURE IS FORMED(SECTION, FIG.3) INTENDED FOR FILLING WITH SOIL OR FRACTIONAL MATERIALS

FIG. 1GEOSTEP® IN THE FOLDED STATE.

FIG.2. APPEARANCE OF THE ROLL.

FIG.3. GEOSTEP® IN WORKING CONDITION.

ADVANTAGES

MOVIE

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DESIGN OF STRENGTHENING NON-FLOODED SLOPES

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CENTRAL RING ROAD, RUSSIAN FEDERATION

HA LONG - VAN DON EXPRESSWAY, VIETNAMHEAVY CUT SLOPE

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RETAINING WALLS

MOVIE

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ALTERNATIVE SOLUTIONS TO REDUCE

PRECIPITATION

GEOMATRIX LOG PLANK ROAD

1 383 916,80 ₽

1 555 298,40 ₽

3 315 927,00 ₽

3 637 836,16 ₽

COST OF CONSTRUCTION

GEOСORD® GEOGRID GEOMATRIX LOG PLANK ROAD

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Application of geosynthetic materials to strengthen weak soil

Igor Meshcherin