scholarly journals Effects of the Installation Method, Loading Condition, and Failure Mechanism on the Behavior of Suction Piles under Monotonic Horizontal Loading

2021 ◽  
Vol 9 (12) ◽  
pp. 1333
Author(s):  
Juhyung Lee ◽  
Jinung Do

A suction pile is a promising option when floating offshore structures are deployed at deep and distant locations. A suction pile is typically used for the foundation system of a mooring system subjected to horizontal loading with a load inclination. In this study, the effects of installation method, loading position, and load inclination on the behavior of a suction pile under monotonic horizontal loading were evaluated via large-scale soil chamber testing. A series of horizontal load tests were performed by varying the loading position at pile embedded lengths of 1/4, 1/2, 2/3, and 3/4. A horizontal load test with a load inclination of 20° was conducted and compared with that of a load inclination of 0°. The failure mechanism of the suction piles under monotonic horizontal loading was assessed via particle image velocimetry (PIV) analysis. The movement of the suction pile during monotonic horizontal loading was elucidated in terms of the horizontal displacement, vertical displacement, and rotation angle. The results of this study show apparent differences between jacking and suction-installed piles and piles under different loading conditions. The PIV analysis shows that the rotational behavior under monotonic horizontal loading can be a critical point to affect the horizontal resistance of the suction pile.

2001 ◽  
Vol 34 (4) ◽  
pp. 1405
Author(s):  
Γ. Δ. ΔΑΝΑΜΟΣ ◽  
Ε. Λ. ΛΕΚΚΑΣ ◽  
Σ. Γ. ΛΟΖΙΟΣ

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peisen Wang ◽  
Hongyan Ding ◽  
Puyang Zhang

The differences in development and situation of karst caves lead to two kinds of karst caves, and the karst cave may be on the pile side or at the pile bottom, which has a different influence on the bearing capacity of pile foundation. The paper presents a numerical analysis of the influence of karst caves at pile side on the bearing capacity of super-long pile foundation in karst areas. According to the size of pile foundation of a real bridge project, this paper modelized karst caves and investigated the karst cave from the effect of length, height, and thickness of roof on horizontal and vertical bearing capacity of pile foundation. The main conclusions can be drawn as: when the horizontal displacement at the top of pile foundation is greater than 0.05 m, the horizontal load is correlated positively with the length of karst cave; when the vertical displacement is greater than 0.07 m, the vertical load is correlated negatively with the thickness of the roof of karst cave. However, the height of karst cave has little effect on the bearing capacity; also the existence of karst cave has little influence on the dynamic response of pile foundation. The results of this study can be important with reference to the design and construction of pile foundations in karst areas.


2014 ◽  
Vol 71 (3) ◽  
Author(s):  
Nur Hidayah A.H. ◽  
Hasanan Md Nor ◽  
Azman M.

This research studies the performance of Concrete Block Pavement (CBP) through the load distribution between the blocks and the jointing sand. Presence of jointing sand in joint provides frictional resistance to prevent the blocks from displaced or moved when the load is applied. Three different sizes of jointing sand (less than 2 mm, 5 mm and 7 mm) with three different jointing widths (2 mm, 4 mm and 6 mm) were used. Laboratory tests were conducted using horizontal load test to compare and investigate the effect by using different jointing sand sizes with different joint widths on the performance of concrete block pavement. It was found that the wider joint width requires coarse jointing sand for good performance of concrete block pavement. Results show that at 2 mm jointing width, it is more appropriate to use jointing sand with a size less than 2 mm and at a 6 mm jointing width it is better to use jointing sand with a size less than 7 mm. It seems to give better results in resisting the horizontal load that been applied before the blocks starts to displace and the pavement failed.


Author(s):  
Somaye Hosseini ◽  
Mahmood Parsaei

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.


2021 ◽  
Vol 11 (8) ◽  
pp. 3615
Author(s):  
Ungjin Kim ◽  
Dae Sang Kim

A full-scale reinforced subgrade for railways (RSR) was constructed, and repetitive and static load tests were performed to analyze the deformation characteristics of reinforced rigid walls with short reinforcements for railway subgrades that require strict displacement restrictions. Load test results were obtained for four sections, in which the reinforcement arrangement (vertical spacing and length) and wall-reinforcement connection method were applied differently, and the behavior of the reinforced rigid wall was observed according to each parameter. A repetitive load of 500 kPa and a static load of 1000 kPa were applied to the outside of the reinforcement area to evaluate the behavior of the subgrade when utilizing short reinforcement. The test results confirmed the reduction of the settlement and horizontal displacement of the wall, owing to the restraining effect of the short reinforcement and rigid wall. In addition, it was observed that the greater the applied load, the greater the influence of the reinforcement on the behavior of the subgrade; this pattern was more marked in loads above the yield of soil.


2020 ◽  
Vol 198 ◽  
pp. 01041
Author(s):  
Qiaoyan Li ◽  
Guowei Ma ◽  
Ping Li ◽  
Zhandong Su

Construction using geofabriform is a new promising technology to build fine grain tailings dam. Large-scale shaking table tests are conducted in this study to investigate the dynamic performances in terms of horizontal acceleration and displacement of the tailings dam with and without geofabriform subject to horizontal earthquakes. Test results indicate that the seismic performance of the tailings dam with geofabriform is significantly better than that of tailings dam without geofabriform. The two types of tailings dams have different failure modes under the action of earthquake. The acceleration amplification factor(Am), vertical displacement and horizontal displacement of the tailings dam with geofabriform under the same seismic acceleration input are smaller than that of the tailings dam without geofabriform, the maximum attenuation amplitude of the Am at the dam slope reaches to 81%. The horizontal displacements of the two types of dams are nonlinearly distributed in the height direction and the geotextile bags of the tailings dam have an upward displacement and are tilted upward. According to the failure mode of the tailings dam with geotextile bags, it is recommended to strengthen the drainage measures and set up anti-slide piles at the bottom of the geotextile bags body to strengthen the tailings dam.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Haifeng Guo ◽  
Dong Ma ◽  
Aijun Yao

This study mainly investigated the variation law and mechanical mechanism of surrounding earth pressure and deformation of an existing tunnel, caused by dewatering, foundation excavation, building loading, and groundwater recovery. According to different dewatering schemes, two modes were established: nonisolated dewatering unloading-loading mode and isolated dewatering unloading-loading mode. Through large-scale similar materials model test, the variation law of deformation and surrounding earth pressure of adjacent tunnel under complex unloading-loading conditions was preliminarily revealed. Based on the size of the prototype project, the test results were further verified by the numerical simulation. The mechanical mechanism of tunnel deformation in different construction stages was analyzed after the comparative study. The results show that the tunnel structure deformation, vertical and horizontal displacement, and torsion occur in the process of building construction. In the nonisolated dewatering unloading-loading mode, the decrease or rise of the groundwater level significantly reduces (maximum 27.85%) or increases (maximum 35.19%) the surrounding earth pressure of the tunnel. The decrease or increase of the horizontal total stress was much greater than that of the vertical total stress, which leads to the deformation of tunnel structure. The vertical displacement of the tunnel is generally settlement, which mainly occurs in the stage of dewatering and building loading, accounting for 83.21%–100.00% and 25.11%–40.34% of the total settlement, respectively. In the stage of foundation pit excavation and groundwater recovery, the tunnel rises. In the horizontal direction, the tunnel moves towards the foundation pit, mainly in the excavation stage, accounting for 82.77%–86.30% of the maximum value. Due to the uneven change of displacement field and stress field of soil outside the foundation pit, the tunnel torsion occurs. In the isolated dewatering unloading-Loading mode, the change of groundwater has little effect on the tunnel. In the stage of excavation and construction load, the variation law of tunnel surrounding earth pressure and deformation is similar in the two modes.


2010 ◽  
Vol 5 (4) ◽  
pp. 555-568
Author(s):  
Eiji KOJIMA ◽  
Hiromichi KUMAGAI ◽  
Koichi TOMISAWA ◽  
Tatsunori MATSUMOTO

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Youichiro Takada ◽  
George Motono

Abstract We applied differential InSAR analysis to the Shiretoko Peninsula, northeastern Hokkaido, Japan. All the interferograms of long temporal baseline (~ 3 years) processed from SAR data of three L-band satellites (JERS-1, ALOS, ALOS-2) commonly indicate remarkable phase changes due to the landslide movement at the southeastern flank of Mt. Onnebetsu-dake, a Quaternary stratovolcano. The area of interferometric phase change matches to known landslide morphologies. Judging from the timing of the SAR image acquisitions, this landslide has been moving at least from 1993 to the present. Successive interferograms of 1-year temporal baseline indicate the temporal fluctuation of the landslide velocity. Especially for the descending interferograms, the positive line-of-sight (LOS) length change, which indicates large subsidence relative to the horizontal movement, is observed in the upslope section of the landslide during 1993–1998, while the negative LOS change is observed in the middle and the downslope section after 2007 indicating less subsidence. The landslide activity culminates from 2014 to 2017: the eastward and the vertical displacement rates reach ~ 6 and ~ 2 cm/yr, respectively. Utilizing high spatial resolution of ALOS and ALOS-2 data, we investigated velocity distribution inside the landslide. During 2007–2010, the eastward component of surface displacement increases toward the east, implying that the landslide extends toward the east. During 2014–2017, the vertical displacement profile exhibits spatially periodic uplift and subsidence consistent with surface gradient, which indicates the ongoing deformation driven by gravitational force. Heavy rainfall associated with three typhoons in August 2016 might have brought about an increase in the landslide velocity, possibly due to elevated pore-fluid pressure within and/or at the base of the landslide material. Also, annual rainfall would be an important factor that prescribes the landslide velocity averaged over 3 years.


2021 ◽  
Vol 13 (5) ◽  
pp. 874
Author(s):  
Yu Chen ◽  
Mohamed Ahmed ◽  
Natthachet Tangdamrongsub ◽  
Dorina Murgulet

The Nile River stretches from south to north throughout the Nile River Basin (NRB) in Northeast Africa. Ethiopia, where the Blue Nile originates, has begun the construction of the Grand Ethiopian Renaissance Dam (GERD), which will be used to generate electricity. However, the impact of the GERD on land deformation caused by significant water relocation has not been rigorously considered in the scientific research. In this study, we develop a novel approach for predicting large-scale land deformation induced by the construction of the GERD reservoir. We also investigate the limitations of using the Gravity Recovery and Climate Experiment Follow On (GRACE-FO) mission to detect GERD-induced land deformation. We simulated three land deformation scenarios related to filling the expected reservoir volume, 70 km3, using 5-, 10-, and 15-year filling scenarios. The results indicated: (i) trends in downward vertical displacement estimated at −17.79 ± 0.02, −8.90 ± 0.09, and −5.94 ± 0.05 mm/year, for the 5-, 10-, and 15-year filling scenarios, respectively; (ii) the western (eastern) parts of the GERD reservoir are estimated to move toward the reservoir’s center by +0.98 ± 0.01 (−0.98 ± 0.01), +0.48 ± 0.00 (−0.48 ± 0.00), and +0.33 ± 0.00 (−0.33 ± 0.00) mm/year, under the 5-, 10- and 15-year filling strategies, respectively; (iii) the northern part of the GERD reservoir is moving southward by +1.28 ± 0.02, +0.64 ± 0.01, and +0.43 ± 0.00 mm/year, while the southern part is moving northward by −3.75 ± 0.04, −1.87 ± 0.02, and −1.25 ± 0.01 mm/year, during the three examined scenarios, respectively; and (iv) the GRACE-FO mission can only detect 15% of the large-scale land deformation produced by the GERD reservoir. Methods and results demonstrated in this study provide insights into possible impacts of reservoir impoundment on land surface deformation, which can be adopted into the GERD project or similar future dam construction plans.


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