INVESTIGATING THE INTERACTION BETWEEN STABILIZED EXCAVATION BY NAILING AND ADJACENT URBAN TUNNELS: CASE STUDY

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Somaye Hosseini ◽  
Mahmood Parsaei
Keyword(s):  
Large Scale ◽  
Lateral Displacement ◽  
Retaining Wall ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Analysis Tool ◽  
Horizontal Distance ◽  
Subway Tunnel

Urban development could be evaluated by considering the transportation and construction industries. The transportation industry development causes an increase in the urban subway lines as well as underground tunnels. Concerning the construction industry, the large-scale buildings development such as commercial malls, high-rise buildings, and underground parking structures may require deep excavations at metropolitan projects. In this paper, a parametric study is carried out by considering the distance of a tunnel from a retaining wall with the staged construction. PLAXIS 2.0D ver.8.5 software is used as an analysis tool. The results show that existing tunnels are affected more than retaining walls during an excavation when the structural response is considered. By increasing the horizontal distance of tunnel center from the wall, lateral displacement and the bending moment of the tunnel would decrease 14% and the vertical displacement and bending moment of tunnel’s Crown would reduce by 15% and 12%, respectively. These interaction effects become negligible after a distance of 5 times the tunnel diameter. Besides, the existence of the tunnel in the vicinity of excavations would increase the top horizontal displacement of the retaining wall by about 13%. It is worthwhile to point out that the current paper is based on a case study on Sharif University multistory underground parking located near the subway tunnel in Tehran city stabilized by deploying a nailing and anchorage system.

scholarly journals The Gujarat, West India, earthquake (Jan 26th 2001). A geodynamic event in an intraplate compressional regime?

2001 ◽  
Vol 34 (4) ◽  
pp. 1405
Author(s):  
Γ. Δ. ΔΑΝΑΜΟΣ ◽  
Ε. Λ. ΛΕΚΚΑΣ ◽  
Σ. Γ. ΛΟΖΙΟΣ
Keyword(s):  
Large Scale ◽  
Lateral Displacement ◽  
Indian Subcontinent ◽  
Plate Boundary ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Lateral Spreading ◽  
Tectonic Deformation ◽  
Epicentral Area ◽  
Surface Ruptures

The Jan. 26, 2001, Ms=7.7 earthquake occurred in Gujarat region of W. India, which lies 200-400 Km away from the active plate boundary zone, between the Indian subcontinent and the Asian plate, along the India-Pakistan border and the Himalayan belt. An Ms=7.7±0.2 earthquake also occurred in the same region in 1819. A zone of co-seismic E-W surface ruptures, 30-40 Km long and 15-20 Km wide, observed near the epicentral area and seems to be associated with pre-existing reverse faults and thrust folds, which were partially reactivated during the recent earthquake. Except the reverse vertical displacement a significant right lateral displacement was also observed along these E-W surface ruptures. This Ms=7.7 seismic event has been also accompanied by a large scale flexural-slip folding, as the absence of significant co-seismic fault displacement and fault scarp shows. This type of compressional tectonic deformation is also confirmed by the focal mechanism of the earthquake and the seismo-tectonic "history" of the area. The NW-SE open cracks, also observed along the same zone, are associated with the right lateral horizontal displacement of the reactivated fault (or branch faults) and the development of local extensional stress field in the huge anticlinic hinges of the co-seismic flexural-slip folds. A large number of ground ruptures, failures and open cracks are also associated with extensive sand boils, liquefaction phenomena and lateral spreading.

scholarly journals Ecological Retaining Wall for High-Steep Slopes: A Case Study in the Ji-Lai Expressway, Eastern China

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peng Jiang ◽  
Jin Li ◽  
Shen Zuo ◽  
Xin Zhuang Cui
Keyword(s):  
Field Experiments ◽  
Lateral Displacement ◽  
Retaining Wall ◽  
Eastern China ◽  
Earth Pressure ◽  
Horizontal Displacement ◽  
Steep Slope ◽  
Protection Scheme ◽  
Steep Slopes

Research on the retaining structures for high-steep slopes is extremely significant because of its real-world applications and far-reaching implications. A flexible geocell-reinforced ecological retaining wall as a high-steep slope protection scheme was developed and applied to the slope protection project of the Ji-Lai Expressway by analyzing the reinforcement mechanism of the geocell used. The lateral displacement and Earth pressure distribution on the flexible ecological retaining wall applied to the high-steep slope were studied using finite element numerical simulations and verified using field experiments. Results reveal that the wall maximum horizontal displacement is 2/3 H away from the wall toe because of the replacement of the upper part of soil. There is an obvious bucking effect on the active Earth pressure around the stiffened site, and the flexible deformation of the retaining wall helped effectively release some of the Earth pressure. Consequently, the measured value is lower than the theoretical value. Through this case study, it is demonstrated that the flexible ecological retaining wall as a slope protection technology can be successfully applied to steep slopes with a height of more than 15 m. Moreover, it brings significant advantages for protecting the ecological environment and improving the highway landscape.

Effect of Existing Building Walls on the Geotechnical Behavior of Foundation under Earthquake Loading

2021 ◽  
Vol 6 (4) ◽  
pp. 100-104
Author(s):  
M. N. Massoud Elsiragy
Keyword(s):  
Large Scale ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Scale Model ◽  
Earthquake Loading ◽  
Three Dimensional Model ◽  
Foundation Soil ◽  
Soil System ◽  
Existing Building ◽  
Building Walls

— Structure’s systems are subjected to additional loads due to earthquakes that may be produces progressive failures. The building illustrates dissimilar categories of failure mechanism for the minor to major earthquake conditions. These structures categorized to the most susceptible type of building has experienced serious hazard or even full failure for the period of seismic activities, therefore their investigation is a complex thing to do. Consequently, this research aims at studying the behaviour of large-scale model of structures constructed with and without brick walls under seismic conditions. The effect of building walls on the performance of the structure during earthquake loading is investigated numerically using PLAXIS 3D software. An eight story building with basement designed on a mat foundation is simulated as three-dimensional model in case of brick walls existing and without brick walls case. The effect of existence such wall building on the stability of foundation soil system is discussed in the form of lateral, horizontal deformation, and foundation acceleration. The studied showed that the reduction of extreme horizontal displacement and bending moment for building foundation with brick walls reached to 43%, and 68% respectively compared to the building without walls. The consideration of wall as filling for super structure significantly reduce the foundation acceleration by as much as 72% of its initial value, which lead to considerable effect of increasing the foundation stability.

Further Comments on Pontryagins Maximum Principle Applied to the Profile of a Beam

1968 ◽  
Vol 72 (690) ◽  
pp. 518-519 ◽  
Author(s):  
L. C. W. Dixon
Keyword(s):  
Phase Space ◽  
Maximum Principle ◽  
Velocity Vector ◽  
Error Function ◽  
Bending Moment ◽  
Space Velocity ◽  
Vertical Displacement ◽  
Hill Climbing ◽  
Horizontal Distance ◽  
Basic Assumptions

Following the appearance of my note on this subject in the July 1967 JOURNAL, Professor Hemp kindly pointed out a mistake in one of the basic assumptions. This has led to a recalculation of the results, and the correct results are given below. a width of beam b lower bound on height of beam d upper bound on height of beam E Modulus of elasticity h (x) height of beam at position x H the Pontryagin Hamiltonian i second moment of area=ah3/12 i length of beam M (x) bending moment = rl, r2 non-dimensional length parameters p density al lengthparam t non-dimensional length parameter=x/l u non-dimensional length parameter=h/l x horizontal distance from base of beam y (x) vertical displacement of the centre-line of beam Y error function in hill climbing sequence Vectors f phase space velocity vector =dX/dt P adjoint vector X non-dimensional state vector

scholarly journals Influence of Soil Liquefaction on the Structural Performance of Bridges During Earthquakes: Showa Bridge as A Case Study

2018 ◽  
Vol 7 (4.20) ◽  
pp. 146
Author(s):  
Mohammed K. Dhahir ◽  
Wissam Nadir ◽  
Mohammed H. Rasool
Keyword(s):  
Lateral Displacement ◽  
Bending Moment ◽  
Sandy Soils ◽  
Soil Liquefaction ◽  
Shallow Foundations ◽  
Structural Performance ◽  
Excess Pore Pressure ◽  
Regular Structures ◽  
Loss Of Contact

Liquefaction is generally defined as the loss of contact between soil particles during shaking (earthquakes), and it usually occurs in saturated loose sandy soils where the timescale is insufficient for the water to drain from the pores, thus increasing the excess pore pressure, and thereby floating the sand particles. For regular structures with shallow foundations, liquefaction normally leads to loss of soil strength, which leads to settlement of foundations. On the other hand, bridges are usually supported with piles foundation, which introduces additional effects during liquefaction. Therefore, this paper examines the possible effects of liquefaction on the structural performance of bridges during earthquakes. Furthermore, the failure of Showa Bridge during the 1964 Nagata earthquake was also discussed and analyzed as an example of the catastrophic effects of liquefaction. The analysis shows that the most influential effect during liquefaction is the increase in the unsupported length of piles, which leads to several adverse effects such as increasing the lateral displacement, reduce the buckling capacity, increase the bending moment, and reduce the shaft capacity of the pile. Finally, recommendations regarding the design of pile supported bridges in seismic areas with liquefiable soils have also been suggested. 

scholarly journals Locomotion in diving elephant seals: physical and physiological constraints

2007 ◽  
Vol 362 (1487) ◽  
pp. 2141-2150 ◽  
Author(s):  
Randall W Davis ◽  
Daniel Weihs
Keyword(s):  
Energy Savings ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Dive Depth ◽  
Elephant Seal ◽  
Dive Duration ◽  
Energetic Cost ◽  
Horizontal Distance ◽  
Flat Bottom ◽  
Elephant Seals

To better understand how elephant seals ( Mirounga angustirostris ) use negative buoyancy to reduce energy metabolism and prolong dive duration, we modelled the energetic cost of transit and deep foraging dives in an elephant seal. A numerical integration technique was used to model the effects of swim speed, descent and ascent angles, and modes of locomotion (i.e. stroking and gliding) on diving metabolic rate, aerobic dive limit, vertical displacement (maximum dive depth) and horizontal displacement (maximum horizontal distance along a straight line between the beginning and end locations of the dive) for aerobic transit and foraging dives. Realistic values of the various parameters were taken from previous experimental data. Our results indicate that there is little energetic advantage to transit dives with gliding descent compared with horizontal swimming beneath the surface. Other factors such as feeding and predator avoidance may favour diving to depth during migration. Gliding descent showed variable energy savings for foraging dives. Deep mid-water foraging dives showed the greatest energy savings (approx. 18%) as a result of gliding during descent. In contrast, flat-bottom foraging dives with horizontal swimming at a depth of 400 m showed less of an energetic advantage with gliding descent, primarily because more of the dive involved stroking. Additional data are needed before the advantages of gliding descent can be fully understood for male and female elephant seals of different age and body composition. This type of data will require animal-borne instruments that can record the behaviour, three-dimensional movements and locomotory performance of free-ranging animals at depth.

Analysis of Mechanical Behavior of Subway Tunnel Constructed by Cover and Cut Reverse Method

2012 ◽  
Vol 446-449 ◽  
pp. 3623-3627
Author(s):  
Tie Cheng Wang ◽  
Yang Gao ◽  
Hai Long Zhao
Keyword(s):  
Bending Moment ◽  
Horizontal Displacement ◽  
Internal Force ◽  
Surrounding Rock ◽  
Diaphragm Wall ◽  
Tunnel Construction ◽  
Construction Process ◽  
Subway Tunnel ◽  
Diaphragm Walls ◽  
Reverse Method

In the paper, not only the internal force and displacement of structure during subway tunnel construction with cover and cut reverse method, but also the displacement field and stress field of surrounding rock are analysed. From the numerical calculation it is shown that the bending moment of diaphragm wall is affected seriously by the distribution and value of the stiffness of horizontal support; the excavation phase of the soil of the second floor underground is the key phase of the construction process because the internal force of structure has large increase; the value of surface settlement, horizontal displacement of diaphragm wall, differential settlement between middle pillar and diaphragm walls all meet the requirements, so the construction is safe and the surrounding buildings are affected slightly.

OCENSA Oil Pipeline Damage due to the Construction of an Embankment for a Highway on Soft Soils: Case Study

2017 ◽  
Author(s):  
Julian Corrales ◽  
Hugo Alberto García García ◽  
Alejandro Marín ◽  
Mauricio Pereira Ordóñez
Keyword(s):  
Lateral Displacement ◽  
Load Capacity ◽  
Horizontal Displacement ◽  
Oil Pipeline ◽  
The Road ◽  
River Flood ◽  
Adjacent Soil ◽  
The Caribbean ◽  
Magdalena River

The OCENSA pipeline crosses the Valley of the Magdalena river flood on its way to the Caribbean Sea, the area of the valley is commonly inundated during the rainy season on shallow waters that remain flooded swamps. These swamps soils are composed by extremely soft peat with thicknesses greater than 15 meters. In June 2016 started the construction of a highway with an embankment of 6 meters in height which was more than 30 meters away from the OCENSA 30” pipeline, Due to the high compressibility of peat, to construct the road the soil is subjected to a process of consolidation and the height of the embankment was corrected adding more material. In July 29 2016 occurs a failure by load capacity on the ground under the embankment and as a result of this fault a lateral displacement of the adjacent soil producing a horizontal displacement in the pipeline of more than 50 cm. This document shows results from the affectation to the pipe and the measures taken to correct the situation.

Study on the Role of Geogrid-Reinforced for Fly Ash Retaining Wall Basing on the Analysis of FLAC3D

2011 ◽  
Vol 368-373 ◽  
pp. 599-603
Author(s):  
Wei Shi ◽  
Jin Han ◽  
Yong Bin Li
Keyword(s):  
Fly Ash ◽  
Safety Factor ◽  
Lateral Displacement ◽  
Retaining Wall ◽  
Vertical Displacement ◽  
Design Parameters ◽  
Finite Element Software ◽  
The Stability ◽  
The Impact

Geogrid-reinforced retaining wall is widely used in civil engineering, the role of geogrid reinforcement and the calculations of reinforcement material in the retaining wall design need further refinement.This paper analyzes the fly ash retaining wall with and without reinforcement by using finite element software of FLAC3D,studys the impact of geogrid-reinforced function on the stability of fly ash retaining wall ,gets the design parameters of geogrid-reinforced fly ash retaining wall.The numerical results show that: the fly ash retaining walls' safety factor is lower when its height is greater than 6m,reinforcement is needed for fly ash retaining wall to improve its safety factor to ensure the stability of retaining wall.Simulate and analyze the 8m high geogrid reinforced fly ash retaining wall,the results show that: increasing the reinforcement spacing can increase the lateral and vertical displacement of geogrid reinforced fly ash retaining wall, the maximum vertical displacement of retaining wall is in the upper wall,maximum lateral displacement occurs in the lower parts of the retaining wall;the reasonable distance of 8m high fly ash retaining wall is 0.8m.

Analysis of the Frame Structure’s Force due to Subway Excavation with Different Horizontal Distance

2012 ◽  
Vol 170-173 ◽  
pp. 1437-1443
Author(s):  
Zhi Qiang Wu ◽  
Yong Li Hu ◽  
Yan Ping Lei
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Bending Moment ◽  
Scale Construction ◽  
Frame Structure ◽  
Horizontal Distance ◽  
Three Dimensional Model ◽  
Finite Element Software ◽  
Engineering Problems ◽  
Engineering Staff

With large-scale construction of subway lines, the influence of subway excavation to the frame structure has been an common problem to be solved. Finite element software was used to create three-dimensional model of the subway with different horizontal distance to the frame structure, and variation of frame structure’s bending moment, axial force, shearing force caused by subway excavation is obtained to analyze. The results will enable engineering staff to have a more comprehensive understanding on this issue, and provide guiding significance for solving similar engineering problems to some extent.

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