New Method for Measurement of Lateral Earth Pressure in Cohesive Soils

1975 ◽  
Vol 12 (1) ◽  
pp. 142-146 ◽  
Author(s):  
K. Rainer Massarsch
Keyword(s):  
Pore Pressure ◽  
Effective Stress ◽  
Basic Concept ◽  
Earth Pressure ◽  
New Method ◽  
Cohesive Soils ◽  
Pressure Measurements ◽  
Lateral Stress ◽  
Lateral Earth Pressure ◽  
The Earth

A new method is described by which the total lateral stress in cohesive soils can be measured. When used in combination with pore pressure measurements, the lateral effective stress, the stress change, and the coefficient of lateral earth pressure at rest, K0, can be calculated. The basic concept of the earth pressure cell and its installation, as described in this report, are simple.

The earth pressure behind full-height frame integral abutments supporting granular fill

2007 ◽  
Vol 44 (3) ◽  
pp. 284-298 ◽  
Author(s):  
Ming Xu ◽  
Chris RI Clayton ◽  
Alan G Bloodworth
Keyword(s):  
Particle Shape ◽  
Radial Strain ◽  
Earth Pressure ◽  
Length Change ◽  
Coarse Sand ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Granular Particle ◽  
Integral Abutments ◽  
Full Height

Compared with conventional bridges, integral bridges have no bearings or joints between the deck and abutments and thus can significantly reduce maintenance requirements and costs over the bridge's lifetime. However, there is uncertainty about the ultimate magnitude of the lateral earth pressure behind such abutments, as they are forced to move with the deck length change caused, for example, by daily and annual variations in the effective bridge temperature. This research investigated the earth pressure that would be expected to occur behind full-height frame integral abutments backfilled by granular materials. Radial strain-controlled cyclic stress path testing has been conducted on coarse sand specimens and a glass ballotini specimen. The results suggest that for integral abutments retaining uniform coarse sand, the lateral earth pressure will experience systematic increases for almost all cyclic strain levels, eventually reaching states of stress close to both active and passive. The mechanism of the buildup of lateral stress is explored, and it appears to be associated with nonspherical granular particle shape. The implications for frame integral abutment design are discussed.Key words: integral abutments, granular, particle shape, earth pressure, stiffness.

Vibratory compaction of coarse-grained soils

2002 ◽  
Vol 39 (3) ◽  
pp. 695-709 ◽  
Author(s):  
K Rainer Massarsch ◽  
Bengt H Fellenius
Keyword(s):  
Effective Stress ◽  
Soil Compaction ◽  
Earth Pressure ◽  
Coarse Grained ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
The Earth ◽  
Vibratory Compaction ◽  
Friction Measurements ◽  
Penetration Tests

The variation of the coefficient of earth pressure in normally consolidated and overconsolidated soil and the effect of soil compaction on the change of the horizontal effective stress are discussed based on cone penetration test (CPT) data. A method is outlined for estimating the increase in the effective earth pressure based on sleeve friction measurements. Soil compaction increases not only soil density, but also horizontal effective stress. Since the cone stress is influenced by the vertical and horizontal effective stress, particularly at shallow depths, the cone stress needs to be adjusted for effective mean stress. A relation is presented for determining the soil compressibility from the adjusted cone stress. A case history is presented where a 10 m thick sand fill was compacted using vibratory compaction. Cone penetration tests indicated a significant increase in cone stress and sleeve friction and a decrease in compressibility (increase in modulus number) due to compaction. The friction ratio was unchanged. It was concluded that the earth pressure about doubled corresponding to an increase in the overconsolidation ratio of at least 5. The results of settlement calculations based on the Janbu method demonstrate the importance of considering the preconsolidation effect in the analyses.Key words: sand, CPTU, vibratory compaction, earth pressure, overconsolidation, modulus number, settlement.

scholarly journals Disturbance Process of Sandy Gravel Stratum Caused by Shield Tunneling and Ground Settlement Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Nie Qingke ◽  
Sun Guang ◽  
Gao Siyuan ◽  
Liu Hongtao ◽  
Zhou Lichao ◽  
...  
Keyword(s):  
Pore Pressure ◽  
Soil Layer ◽  
Earth Pressure ◽  
Surface Settlement ◽  
Urban Rail Transit ◽  
Shield Tunneling ◽  
Tunnel Excavation ◽  
Sandy Gravel ◽  
Working Surface ◽  
The Earth

This paper analyzed the earth pressure, pore pressure, and surface settlement of the Luoyang urban rail transit tunnel in a sandy gravel stratum (Henan Province, China) under different burial depths by using field measurement methods. The results showed that the earth pressure as well as pore pressure of the soil layer above the working surface increased sharply and reached their maximum values when the cutter head of the shield gradually crossed the working surface. During the completion of synchronous grouting, the earth pressure and pore pressure increased slightly; when shield tunneling passed through the working surface, the earth pressure is smaller than the original earth pressure due to the unloading effect. The surface settlement curve above the tunnel took on a “V” shape after the completion of the left-side tunnel excavation, conforming to the normal distribution pattern. The surface settlement curve above the two tunnels took on a “W” shape after the completion of the right-side tunnel excavation, which is in good agreement with the proposed theoretical calculations. The findings of this study can help for better understanding the control of safety risk during shield construction.

scholarly journals Lateral Earth Pressure behind Walls Rotating about Base considering Arching Effects

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Dong Li ◽  
Wei Wang ◽  
Qichang Zhang
Keyword(s):  
Conversion Factor ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Soil Mass ◽  
Shear Stresses ◽  
Key Factors ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Common Effect ◽  
The Common

In field, the earth pressure on a retaining wall is the common effect of kinds of factors. To figure out how key factors act, it has taken into account the arching effects together with the contribution from the mode of displacement of a wall to calculate earth pressure in the proposed method. Based on Mohr circle, a conversion factor is introduced to determine the shear stresses between artificial slices in soil mass. In the light of this basis, a modified differential slices solution is presented for calculation of active earth pressure on a retaining wall. Comparisons show that the result of proposed method is identical to observations from model tests in prediction of lateral pressures for walls rotating about the base.

Model for predicting displacement-dependent lateral earth pressure

2009 ◽  
Vol 46 (8) ◽  
pp. 969-975 ◽  
Author(s):  
Guoxiong Mei ◽  
Qiming Chen ◽  
Linhui Song
Keyword(s):  
Earth Pressure ◽  
The State ◽  
Passive State ◽  
Test Results ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Proposed Model ◽  
Pressure Changes ◽  
The Relationship ◽  
Good Agreement

A model for predicting displacement-dependent lateral earth pressure was proposed based on an earth pressure – displacement relationship commonly observed in practice. The proposed model is a monotonically increasing and bounded function, with an inflection point at the displacement of s = 0 at which the earth pressure changes from the intermediate active state (the state between active and at-rest) to the intermediate passive state (the state between at-rest and passive). The proposed model can predict the relationship between earth pressure and retaining structure movement for any condition intermediate to the active and passive states, which was verified by the experimental data reported in published literature. The predicted lateral earth pressure coefficients are in good agreement with the test results of model tests reported in the literature.

Determination of apparent earth pressure diagram for anchored walls in c–φ soil with surcharge

2020 ◽  
Vol 17 (4) ◽  
pp. 481-489
Author(s):  
Seyyed Pouya Alavinezhad ◽  
Hadi Shahir
Keyword(s):  
Retaining Wall ◽  
Ground Surface ◽  
Earth Pressure ◽  
Ground Level ◽  
Content Type ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Real Distribution ◽  
Strain Modeling

Purpose The purpose of this study is to present a diagram for the lateral earth pressure of c–φ soils exerted on anchored walls in presence of surcharge. Design/methodology/approach To this end, two-dimensional plane strain modeling of anchored wall was carried out in Plaxis software. To validate the numerical model, two excavations with different specifications were simulated and the model results were compared with the available results. Subsequently, a parametric analysis was done and based on its results, a diagram was proposed for the lateral earth pressure of c–φ soils including the surcharge effects. Findings The proposed diagram without the surcharge and cohesion effects is a trapezoidal with zero value at the ground surface that is linearly approaching the apparent earth pressure of sand according to Terzaghi and Peck (1967) at 0.1H (H: wall height). The surcharge and cohesion effects at the ground level is 4 Ka*q and 0, respectively, and below 0.1H, they are treated as the same way for lateral earth pressure of a retaining wall. It should be emphasized that the apparent pressure diagram for design does not resemble the real distribution of earth pressure against the wall and it is for calculating the values of the anchors loads. Originality/value The available diagrams to determine the earth pressure exerted on the anchored walls are related to sandy or clayey soils and do not take the presence of surcharge into account. Thus, the proposed diagram is quite original and different from the previous ones.

Seismic reconstruction of the in situ anisotropic stress field for caprock integrity in the Athabasca oil-sands basin, Canada

2019 ◽  
Vol 7 (1) ◽  
pp. T221-T229 ◽  
Author(s):  
Draga A. Talinga ◽  
Carmen C. Dumitrescu
Keyword(s):  
Stress Field ◽  
Pore Pressure ◽  
Effective Stress ◽  
Vertical Stress ◽  
New Method ◽  
3D Seismic ◽  
Principal Stresses ◽  
Anisotropic Stress ◽  
Clearwater Formation ◽  
Formation Pore Pressure

In the Athabasca Basin of Alberta, Canada, the Lower Cretaceous McMurray Formation reservoir is overlain by the Clearwater Formation, a regionally continuous layer composed predominantly of shales with interbedded mudstones. The shales form the reservoir caprock and have the role of blocking the vertical migration of the steam from thermal oil production by confining the stresses and the deformations. We have developed a new method for the 3D seismic reconstruction of the anisotropic stress field, which accounts for the formation pore pressure and the effective stress. We integrated anisotropy estimated from dipole sonic logs with formation pore pressure data from piezometers and elastic properties obtained from multicomponent seismic inversion. The method combines the Terzaghi effective stress with the Schoenberg and Sayers elastic stiffness matrix for horizontal transversely isotropic (HTI) fractured materials. The key points of this method are the estimation of the formation pore pressure in the abnormal regime of the Clearwater Formation, the normal fracture weakness parameter (based on constraints on the compressional velocity of the intact rock under the HTI assumption), and the 3D seismic anisotropic stress field. We expressed the total vertical stress as the weight of the overlying formations, and the total minimum and maximum horizontal stresses as a combination of the total vertical stress, normal fracture weakness, formation pore pressure, Biot-Willis coefficient, and Lamé elastic constants. The effective principal stresses are estimated from the equivalent total principal stresses and the formation pore pressure multiplied by the Biot-Willis coefficient. We observed excellent consistency between the calculated total minimum horizontal stress and mini-frac values. This new method for the 3D seismic reconstruction of the anisotropic stress field allows for the assessment of the caprock integrity and for operational savings based on a reduced number of mini-frac measurements, and it can be used for time-lapse stress estimation within the thermal production reservoir.

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