scholarly journals Research on the Earth Pressure and Internal Force of a High-Fill Open-Cut Tunnel Using a Bilayer Lining Design: A Field Test Using an FBG Automatic Data Acquisition System

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1487 ◽  
Author(s):  
Tianyuan Xu ◽  
Mingnian Wang ◽  
Li Yu ◽  
Cheng Lv ◽  
Yucang Dong ◽  
...  
Keyword(s):  
Field Test ◽  
Soil Column ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Internal Force ◽  
Automatic Data ◽  
The Earth ◽  
New Type ◽  
Earth Pressure Coefficient ◽  
Two Stages

When there are railway tunnels on both sides of a valley, a bridge is usually built to let trains pass. However, if the valley is very close to an urban area, building an open-cut tunnel at the portal and then backfilling it to create available land resources for the city and to prevent excavation slag from polluting the environment would be a wise choice. This has led to the emergence of a new type of structure, namely, the high-fill open-cut tunnel. In this paper, by performing an automatic long-term field test on the first high-fill open-cut tunnel using a bilayer design in China, the variations of earth pressure and structural internal force during the backfilling process were obtained, and different tunnel foundation types were studied. The results showed that the earth pressure significantly exceeded the soil column weight, with a maximum earth pressure coefficient between 1.341 and 2.278. During the backfilling process, the earth pressure coefficient increased at first and then decreased slowly to a relatively stable value, and a stiffer foundation would make the structure bear higher earth pressure (1.69 times the normal one observed during monitoring). The change of internal force had two stages during backfilling: before the backfill soil reached the arch crown, the internal force of the lining changed slowly and then grew linearly as the backfill process continued. Moreover, the axial force ratio of the inner and outer linings was close to their thickness proportion, and the interaction mode between the two layers was very similar to the composite beam.

Exact determination of gravity stresses in finite elastic slopes: Part II. Applications

1983 ◽  
Vol 20 (1) ◽  
pp. 55-60 ◽  
Author(s):  
V. Silvestri ◽  
C. Tabib
Keyword(s):  
Exact Solution ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Influence Diagrams ◽  
A Value ◽  
The Earth ◽  
Exact Determination ◽  
Earth Pressure Coefficient ◽  
Numerical Finite Element

Influence diagrams are presented for the gravity stresses arising in excavated finite elastic slopes inclined at various angles, −β (β = π/2, π/3, π/4, π/6, and π/8), with respect to the horizontal. These influence diagrams are calculated for a value of the earth pressure coefficient at rest, K0, equal to 0.50. Several examples are worked out and adequately illustrate the application of the influence charts and of the general solution. Finally, the results obtained from the exact solution are compared with those published in the literature, which were obtained by means of numerical (finite element) and experimental (photoelasticity) methods.

An examination of some theories of earth pressure on shaft linings

1977 ◽  
Vol 14 (1) ◽  
pp. 91-106 ◽  
Author(s):  
E. G. Prater
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Failure Surface ◽  
Cohesionless Soils ◽  
The Earth ◽  
Earth Pressures ◽  
Coulomb Type ◽  
Earth Pressure Coefficient ◽  
The One ◽  
Similar Theory

Various theories for determining the earth pressure on shaft linings in cohesionless soils are discussed, and results are presented for a Coulomb-type analysis with a conical sliding surface. The assumed shape of the failure surface approximates closely the one given in published results obtained by the method of characteristics. The simplicity of the cone permits an investigation of a number of parameters, e.g. the earth pressure coefficient on radial planes, which turns out to be a decisive parameter in the analysis, and accounts for the widely differing published values for earth pressures on shaft linings. Certain theories could lead, especially at greater depths, to rather conservative designs.A similar theory is also presented for earth pressures on shafts in cohesive soils. In this case the possibility of base failure must be considered as well, and it is shown that this might be the deciding failure mechanism.

scholarly journals Numerical investigation of earth pressure coefficient along central line of backfilled stopes

2017 ◽  
Vol 54 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Mohamed Amine Sobhi ◽  
Li Li ◽  
Michel Aubertin
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Central Line ◽  
Simple Expression ◽  
Active Earth Pressure ◽  
Principal Stresses ◽  
The Earth ◽  
Earth Pressure Coefficient ◽  
Backfilled Stopes ◽  
Key Parameter

The earth pressure coefficient K, defined as the horizontal to vertical normal (effective) stresses ratio (σh/σv), is a key parameter in analytical solutions for estimating the stresses in backfilled stopes. In the case of vertical stopes, the value of K has sometimes been defined using the at-rest earth pressure coefficient K0, while others have applied Rankine’s active earth pressure coefficient Ka. To help clarify this confusing situation, which can lead to significantly different results, the origin and nature of the at-rest and Rankine’s active coefficients are first briefly recalled. The stress state in backfilled stopes is then investigated using numerical simulations. The results indicate that the value of K can be close to Ka for cohesionless backfills along the vertical central line (CL) of vertical stopes, due to sequential placement and partial yielding of the backfill. For inclined stopes, simulations show that the ratio between the minor and major principal stresses (σ3/σ1) along the CL in the backfill, which differs from σh/σv, can also be close to Ka. A simple expression is shown to represent the horizontal to vertical stresses ratio σh/σv (= K) along the CL of such inclined stopes well. A discussion follows on the effects of backfill properties and simulation approach.

An assessment of the earth pressure coefficient in overconsolidated clays

Géotechnique ◽  
2009 ◽  
Vol 59 (10) ◽  
pp. 825-838 ◽  
Author(s):  
V. SIVAKUMAR ◽  
T. NAVANEETHAN ◽  
D. HUGHES ◽  
G. GALLAGHER
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
The Earth ◽  
Overconsolidated Clays ◽  
Earth Pressure Coefficient

Experiences with shored excavations

1987 ◽  
Vol 24 (2) ◽  
pp. 267-278
Author(s):  
W. A. Trow
Keyword(s):  
Soil Mechanics ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Foundation Engineering ◽  
Active Earth Pressure ◽  
Case Histories ◽  
Pressure Coefficients ◽  
The Earth ◽  
Earth Pressure Coefficient ◽  
Selection Of

This paper considers shoring of excavations associated with construction of buildings with particular reference to the selection of the earth pressure coefficient. The empirical criteria, given by R. B. Peck and other participants at the International Conference on Soil Mechanics and Foundation Engineering in Mexico City in 1969, are examined. Several case histories of deep excavations are given where acceptable deformations were experienced using active earth pressure coefficients in shoring design. Where failure occurred, it was attributed to causes unrelated to the selection of earth pressure coefficient. Key words: shoring, earth pressure coefficient, deformations.

Lateral Earth Pressure Coefficient of Soils Subjected to Freeze–Thaw

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Xiaodong Zhao ◽  
Guoqing Zhou ◽  
Bo Wang ◽  
Wei Jiao ◽  
Jing Yu
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Saturated Soil ◽  
Frozen Soils ◽  
Freeze Thaw ◽  
Lateral Earth Pressure ◽  
Soil Deposits ◽  
Earth Pressure Coefficient ◽  
Water Saturated

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (Fnonuni–Tuni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient  K0, and  K0 decrement under the horizontal Fnonuni–Tuni was greater than that under the vertical Fnonuni–Tuni. The measured  K0 for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical Fnonuni–Tuni and horizontal Fnonuni–Tuni treatments. The anisotropies of  K0 under the horizontal Fnonuni–Tuni were greater than that under the vertical Fnonuni–Tuni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.

scholarly journals Experimental Study on At-rest Lateral Earth Pressure Coefficient of Cemented Clay

2019 ◽  
Vol 304 ◽  
pp. 042014
Author(s):  
Zhiqiang Wu ◽  
Zhengyin Cai ◽  
Kai Xu ◽  
Yunfei Guan ◽  
Yinghao Huang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Pressure Coefficient ◽  
Earth Pressure ◽  
Lateral Earth Pressure ◽  
Earth Pressure Coefficient

“Nonlinear” characteristics of the static earth pressure coefficient in thick alluvium

2009 ◽  
Vol 19 (1) ◽  
pp. 129-132 ◽  
Author(s):  
Zhi-wei XU ◽  
Kai-hua ZENG ◽  
Zhou WEI ◽  
Zhi-qiang LIU ◽  
Xiao-dong ZHAO ◽  
...  
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Nonlinear Characteristics ◽  
Earth Pressure Coefficient
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