Showing papers on "Lateral earth pressure published in 1988"

Foundation analysis and design. fourth edition

Abstract: The fourth edition of this textbook has been rewritten and provides state-of-the-art (soa) and state-of-practice (sop) methods in foundation engineering. This edition places emphasis on computer methods and finite element methods (fem), involving matrix methods, to reflect the use of the pc and fem techniques. The following chapters are presented: (1) introduction; (2) geotechnical properties; laboratory testing index settlement and strength correlations; (3) exploration, sampling and in-situ soil measurements; (4) bearing capacity of foundations; (5) foundation settlements; (6) improving site soils for foundation use; (7) factors to consider in foundation design; (8) spread footing design; (9) special footings and beams on elastic foundations; (10) mat foundations; (11) lateral earth pressure; (12) mechanically stabilized earth and concrete retaining walls; (13) sheet-pile walls - cantilevered and anchored; (14) braced, tieback and slurry walls for excavations; (15) cellular cofferdams; (16) single piles -static capacity; (17) single piles -dynamic analysis; (18) pile foundations -groups; (19) drilled piers or caissons; (20) design of foundations for vibration control.

Wave-induced forces on buried pipelines

Abstract: Ocean waves induce dynamic pressure responses in permeable seabeds which result in dynamic loads on buried pipelines. An analytical model is developed for estimating the pore pressure in the soil and the resulting pressure force on buried pipelines. It is assumed that the seabed is rigid, homogeneous, and porous with isotropic permeability, that the pore water is incompressible, that fluid flow in the soil is modeled by Darcy's Law, and that the seabed is infinitely deep. A solution is developed for a circular, rigid pipeline using conformal mapping techniques. The solution is compared with the results of both small and large‐scale tests; reasonable agreement is obtained for the small‐scale tests. Wave‐induced seepage forces are evaluated by integrating the pressure distribution over the pipe surface. The magnitude of the force remains constant but the direction rotates around the cylinder once with the passage of each wave. This force may be of sufficient magnitude to be an important consideration in the...

Settlement of shallow foundations on granular soils

Abstract: A conceptual framework for understanding the effects of overconsolidation in reducing the compressibility of all types of soils is presented. A generally applicable method for estimating the settlement of footings on granular soils is presented. The procedure uses a combination of dilatometer and cone-penetration test results to identify the preconsolidation pressure, while soil moduli—either Young’s modulus or constrained modulus, depending on the boundary conditions—are obtained from the dilatometer test results. Calibration chamber test results are used to adjust the dilatometer moduli for the effects of stress path and for disturbance due to insertion of the instrument. Detailed examples are given to illustrate the use of the method and to compare the results obtained with those calculated using currently accepted methods for estimating settlements.

Closed-form heave solutions for expansive soils

Abstract: During the past decade, the theory for heave prediction has developed within the context of unsaturated soil behavior and has become a valuable tool for geotechnical practice. The laboratory procedures for testing expansive soils have also been essentially standardized. The heave prediction theory is briefly reviewed in this paper, and the importance of sampling disturbance is emphasized. Closed-form solutions are presented for several possible situations that can be applied to engineering practice. In all cases, the soil deposit is assumed to be homogeneous, and the swelling pressure is assumed to be constant with depth. The closed-form solutions are presented for the calculation of total heave when: (1) A portion or the entire "active depth" is wetted; (2) a portion of the expansive soil is excavated; and (3) the excavated portion is backfilled with a nonexpansive soil.

Reinforcement Extensibility in Reinforced Soil Wall Design

Abstract: There are many types of reinforcing materials and systems available for the construction of reinforced soil walls Of the many types, the Reinforced Earth system developed by Vidal (1966) in France has predominated and has provided the basis for most theoretical and empirical knowledge of the behavior of reinforced soil walls The Reinforced Earth system has a number of distinguishing characteristics that include: steel reinforcing elements that have tensile moduli on the order of 2 × 108 kPa (3 × 107 lbs/in2); reinforcing elements that are discrete strips, approximately 50 mm (2 in) wide and 5 mm (02 in) thick; and concrete facing (skin) elements that can individually undergo limited translation and rotation in response to movements in the reinforced fill or settlements of the foundation soils

Results of Class a Predictions for the RMC Reinforced Soil Wall Trials

Abstract: The NATO Advanced Workshop on Application of Polymeric Reinforcement in Soil Retaining Structures was undertaken to critically assess the state-of-the-art in polymeric reinforced soil retaining structures. In order to establish common ground for discussions, a number of participants were asked to make detailed Class A predictions of the performance of two large-scale model polymeric reinforced soil walls constructed within the RMC Retaining Wall Test Facility.

Polymerically Reinforced Retaining Walls and Slopes in North America

Abstract: This paper presents a summary of reported polymerically reinforced soil wall and slope projects constructed in North America. The projects included walls and slopes where the reinforcement was used to resist lateral earth pressures and prevent internal failure through the face or toe of the structure. Projects where reinforcement has been used to provide increased stability against deep seated failure of embankments were not included. Specific emphasis was placed on projects that have been instrumented and monitored such that performance assessments could be made.

Fem analysis of polymer grid reinforced-soil retaining walls and its application to the design method ---proceedings of the international symposium on theory and practice of earth reinforcement, fukuoka, kyushu, japan, 5-7 october 1988

Abstract: Finite element analyses for the polymer grid reinforced-soil retaining walls are performed using the method which is capable of taking account of the displacement dependence property of the pull-out resistance of the polymer grid in soils. The reduction effect of the earth pressure acting on the wall and the wall deformation by the reinforcement is discussed. Furthermore, the application of the analytical results to the design method is proposed.(a) for the covering abstract of the symposium see IRRD 818063.

Earth pressures on retaining walls and abutments: a report of the british geotechnical society's informal discussion held at the institution of civil engineers on jan 13 1988

Abstract: The author reports on the January 1988 Geotechnical Society's informal discussion held at the Distribution of Civil Engineers, London. The three main speakers were I F Symons and R T Murray of TRRL who presented results from pilot-scale and full-scale studies and M D Bolton of Cambridge University who discussed the development of a new design code for earth retaining structures. The pilot-scale facility described comprised both a rigid reinforced concrete wall and a movable metal wall. Studies were made of compaction pressures using full-size plant and construction techniques as well as the effects of wall movement on earth pressures. Field studies showed that relief of vertical stress caused by wall friction which could be significant with reinforced earth walls. Long-term conditions could be uncertain when using cohesive backfill and the available deflection of a more flexible wall may be taken up during the compaction process. Traffic loading effects were deliberately omitted from the proposed design code since if high residual stresses were already present due to compaction, further stress increases would generally not occur because traffic loadings were less severe than that of the compaction plant. (TRRL)

Ultimate Capacity of Earth-Covered Slabs

Abstract: Three tests were conducted on identical one‐way reinforced concrete slabs. The tests were conducted using water over a waterproof membrane to apply a uniform surface pressure under three conditions: (1) With the test slab surface flush; (2) with the slab surface one foot (30.5 cm) deep in a clay soil backfill; and (3) with the slab surface one foot (30.5 cm) deep in a sand backfill. The reaction structure supporting the slabs was rigid enough to effectively prevent translation or support rotation at the clamped edges and to prevent in‐plane thrust in the slab generated by lateral earth pressures. The surface flush slab failed at about 174 psi (1.22 MPa), failure in the clay backfill occurred at about 171 psi (1.20 MPa), and failure in the sand backfill occurred at about 835 psi (5.83 MPa), overpressure. The almost fivefold increase in capacity in the sand backfill was due primarily to soil arching in the high shear strength sand backfill. These test results indicate that soil arching is much more importan...

Dilatometers settle in

Abstract: The benefits of the dilatometer test DMT are described. This geotechnical in situ testing tool was developed and patented by an Italian professor and engineer named Silvano Marchetti. The DMT delivers, according to the author, a surprising combination of accuracy, reproducibility, ruggedness, economy, and versatility. Professor Marchetti combined the simplicity and economy of a penetration test with the sophistication of a test that also measures an in situ stress and modulus. The DMT is most useful for the rapid calculation of expected settlements in many types of soil, but it also has many other uses. For those unfamiliar with the DMT, the article explains how a technician operator uses a drill rig or other suitable equipment to push or drive the blade into the soil to be tested, stopping at suitably spaced test depth intervals as close as 150 mm. At each depth the operator uses gas pressure to expand and deflate a stainless steel membrane horizontally in the soil and obtains four data readings. The data is then interpreted to reveal such qualities as soil type, in situ lateral stress, the excess hydrostatic pore pressure, undrained shear strength, the friction angle and in situ pressure in sands, to name a few, all for use in any rational design procedures.

Application of Finite Element Techniques to the Analysis of Reinforced Soil Walls

Abstract: The beneficial effect of incorporating tensile inclusions within a soil mass is well recognized and has been demonstrated by the successful construction of numerous reinforced soil walls using facings ranging from relatively rigid full face concrete panels to a flexible geotextile “skin”, and reinforcement ranging from relatively stiff steel strips or meshes to geotextile sheets of low stiffness. Design methods for reinforced-soil walls (which are discussed in detail in other papers at this workshop) are typically based on limit equilibrium calculations which do not explicitly consider deformations or interaction between the inclusion and the soil.

Anti-earth pressure wall

Abstract: PURPOSE: To obtain sufficient strength at a low cost and allow vegetation by burying a reinforcing fiber grid inside, placing a soft material such as soil mortar, and integrally constructing a bottom plate and a wall body. CONSTITUTION: The ground E is excavated, the bottom face of the excavated position is leveled, broken stones 3 are spread, and a fiber grid 7 is assembled on them. A formwork is assembled, a soft material 6 such as soil mortar is placed in it, and a bottom plate 3 and a wall body 5 are integrally constructed. The weakness of the binding power of the soft material 6 is supplemented by the fiber grid 7, sufficient strength against the earth pressure is obtained, hardening is accelerated, and construction can be quickly performed. COPYRIGHT: (C)1990,JPO&Japio

Method of constructing underground structures with bored piles

Abstract: In a method of constructing an underground structure with walls, placed from above, of overlapped, tangent or staggered bored piles, the bored piles are connected to a subsequently constructed, load-bearing inner shell to form a composite supporting structure which can absorb the effects of water pressure and/or earth pressure.

High restraint pressure shearinig soil tank

Abstract: PURPOSE:To enable response analysis with a higher certainty, by a method wherein a shearing soil tank which is soft and elastic like rubber and with a greater mechanical strength is arranged in an air pressure tank with the lower end thereof fixed and vibration is applied thereto obtain a physical value closer to an actual value. CONSTITUTION:A shearing soil tank 2 which is soft and elastic like rubber and with a greater mechanical strength is arranged in an air pressure tank 1 with the lower end thereof fixed. A soil sample taken is put into the shearing soil tank 2 and made ready to dry and compact. A sensor such as accelerometer, strain gauge, soil pressure meter and interval hydraulic gauge is buried into the sample and then, pressure is applied to the pressure tank 1 corresponding to rock pressure at a sampling depth of the sample making a pressure adjust ment with a pressure reducing valve 1j. When a horizontal base 4 or a low acceleration hard to gain with the vibration base 4 is applied, vibration is pro vided from outside the pressure tank 1 with a free vibration jig 3 provided on the shearing oil tank 2.

Underground cavity structure with a cover slab

Abstract: Arrangement for transmitting earth and water pressures to underground cavity structures, in particular road tunnels, which essentially have cast-in-situ walls, diaphragm walls, bored piles and suchlike supporting structures, the loading by earth pressure and inflow of water being separated by water- permeable walls provided on the outside of the structure. In this case, the loading by the earth pressure is absorbed by the supporting structure (bored piles 1), and the static stress of the inflow of water is restrained by the adjoining cavity.