Closure to “Construction Pore Pressures in an Earth Dam”

This study examined the challenges of water resource development and management in Zing town,Taraba State, Nigeria. The study considered issues of sources of water supply in Zing town, the nature of water challenges, impacts of the water challenges on the socio-economic life of the people, water management strategies and prospect of urban water resource development in the study area. 110 questionnaires were systematically administered in ten streets that were purposively selected in Zing town. The data were analyzed using descriptive statistics. The result of the finding indicates that majority (45.5%) of the respondent have their water source from borehole, 18.2% streams, 18.2% hand dug wells and 9.1% from other sources (mostly water vendors). The study shows that 68.2% of the respondents had their water point located outside their households, while only 31.8% claimed to have their water sources located within their compounds (this is mostly hand dug wells). The nature of water challenge in the area ranges from severe (50%), not severe (27.3%) and normal (22.7%). The results also shows that only 34% of respondents claimed to have access to sufficient water daily, while 66% of the respondents hardly have access to sufficient water on daily basis. The study shows that the water management strategy adopted mostly by the respondent ranges from storing water in large container (48.2%), reduce water use (29.1%), increase amount spent on water (13.6%) and others 9.1% (mainly re-use of water). The prospect of water resource development in the study area is very bright with the proposal of a small earth dam in Monkin settlement by the Federal Government of Nigeria. The Monkin small earth dam which is meant to generate 500KW of electricity can be integrated into an urban water supply project in the area. This will assure more reliable water supply all year round. It will also help to overcome some of the challenges of servicing the hand pumps which rendered them inadequate when they break down. This study recommends the need to replace the old and obsolete borehole equipment with new ones and increase the number of boreholes to meet the increasing water demand in the area.

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Downdrag Measurements on a 160-Ft Floating Pipe Test Pile in Marine Clay

Canadian Geotechnical Journal ◽

10.1139/t72-014 ◽

1972 ◽

Vol 9 (2) ◽

pp. 127-136 ◽

Cited By ~ 28

Author(s):

M. Bozozuk

Keyword(s):

Skin Friction ◽

Compressive Load ◽

Marine Clay ◽

Positive Skin ◽

Negative Skin Friction ◽

Pore Pressures ◽

Excess Pore Pressures ◽

Test Pile ◽

Excess Pore

Large negative skin friction loads were observed on a 160 ft (49 m) steel pipe test pile floating in marine clay. The test pile was driven, open-ended, on the centerline of a 30 ft (9 m) high granular approach fill on the Quebec Autoroute near Berthierville. Since the installation was made in 1966 the fill has settled 21 in. (53 cm), dragging the pile down with it. Negative skin friction acting along the upper surface of the pile was resisted by positive skin friction acting along the lower end as it penetrated the underlying clay. Under these conditions the pile compressed about [Formula: see text] (2 cm). Analysis of the axial strains indicated that a peak compressive load of 140 t developed at the inflection point between negative and positive skin friction 73 ft (22 m) below the top of the pile. Negative and positive skin friction acting on the upper surface of the pile exceeded the in situ shear strength and approached the drained strength of the soil where excess pore water pressures had dissipated. At the lower end where the positive excess pore pressures were high and relative movement between the pile and the soil was large, the positive skin friction approached the remoulded strength as measured with the field vane. Skin friction was increasing, however, as positive escess pore pressures dissipated.This paper shows that skin friction loads are related to the combination of (a) in situ horizontal effective stresses, (b) horizontal stresses due to embankment loads, and (c) horizontal stresses due to differential settlement of the fill.

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Numerical and experimental modelling of seepage in homogeneous earth dam with combined drain

ISH Journal of Hydraulic Engineering ◽

10.1080/09715010.2021.1891469 ◽

2021 ◽

pp. 1-11

Author(s):

Azam Kouhpeyma ◽

Fouad Kilanehei ◽

Mahmood Hassanlourad ◽

Reza Ziaie-Moayed

Keyword(s):

Earth Dam ◽

Experimental Modelling

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Analysis of the mechanical properties of methane hydrate-bearing sands with various pore pressures and confining pressures

Journal of Natural Gas Science and Engineering ◽

10.1016/j.jngse.2020.103786 ◽

2020 ◽

pp. 103786

Author(s):

Shi Shen ◽

Yanghui Li ◽

Xiang Sun ◽

Lei Wang ◽

Yongchen Song

Keyword(s):

Mechanical Properties ◽

Methane Hydrate ◽

Pore Pressures ◽

Confining Pressures

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An investigation on dam settlement during and end of construction using instrumentation data and numerical analysis

SN Applied Sciences ◽

10.1007/s42452-021-04306-z ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

Behrang Beiranvand ◽

Mehdi Komasi

Keyword(s):

Numerical Analysis ◽

Multivariate Regression ◽

Initial Conditions ◽

Horizontal Displacement ◽

Behavioral Model ◽

Critical Section ◽

Earth Dam ◽

Dam Construction ◽

Good Match ◽

Consolidation Settlement

AbstractIn the present study, using instrumentation data regarding vertical and horizontal displacement of the dam have been analyzed. Also, the largest and most critical section of the Marvak earth dam is modeled with the behavioral model of the Mohr–Coulomb by GeoStudio software. Numerical modeling of the dam has been done considering the actual embankment conditions and to analyze the changes of the immediate settlement during construction and the consolidation settlement just after construction and initial impounding. The outcomes of instrumentation and numerical analysis at the end of Marvak dam construction showed a settlement between 20 and 500 mm. The results show that the settlement will occur during the construction at the upper levels and the end of construction at the middle levels of the dam. By comparing observed and predicted data, multivariate regression and the explanation coefficient criterion (R2) was found to be R2 = 0.9579, which shows a very good correlation between observed and predicted data, and represents a good match for the settlement points and their location with the initial conditions of the design, and the behavior of the dam in terms of the settlement is found to be stable.

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