Calculation of Lateral Soil Pressure at the Hydraulic Construction and its Sustainability on the Stone Bed

2020 ◽  
Vol 1006 ◽  
pp. 149-157
Author(s):  
Irina A. Karpiuk ◽  
Vasyl M. Karpiuk ◽  
F.R. Karpiuk
Keyword(s):  
Stress Condition ◽  
Slip Surface ◽  
Normal Pressure ◽  
Soil Pressure ◽  
Elastic Zone ◽  
Technical Theory ◽  
Strip Loading ◽  
Internal Side ◽  
Definition Of ◽  
Ultimate Condition

The engineering method of analysis of pressure of a ground on flat walls is offered at presence of combine strip superficial loading in view of seismic influences. It is recommended to determine a situation of an internal slip surface dividing an elastic zone from area of limiting balance, on the basis of the technical theory of the ultimate stress condition. Proceeding from a situation of an internal and external slip plane, size of strip loading on the fill, the pressure of a ground which is taking place in an ultimate condition, on an internal slip surface of is determined on developed by P. Yakovlev to the specified Coulomb's method [1], and on an internal side of a retaining structure on the basis of the Boussinesq decision. In comparison with the earlier developed way it is offered specified according to the Boussinesq theory a method of definition of pressure transmitted by bed on a ground of the basis and, as a consequence more reasonable definition of safety factor of stability of a structure. Thus, curvilinear normal pressure diagram in a ground under a sole of lay is replaced on isosides trapeziform.

scholarly journals An Experimental Study of Horizontal Bearing Capacity of Vertical Steel Floral Tube Micropiles with Double Grouting

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Kaiyang Wang ◽  
Yanjun Shang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Slip Surface ◽  
Bending Moment ◽  
Shear Capacity ◽  
Soil Reinforcement ◽  
Scale Model ◽  
Soil Pressure ◽  
Floral Tube ◽  
Grouting Pressure

This paper examines the performance of a novel technology, vertical steel floral tube micropiles with double grouting. It is the combination of micropile technology and double grouting technology. A large-scale model tank was applied to impart horizontal bearing capacity, and the slope soil pressure and flexural performance of the micropile were investigated under four experimental conditions. The peak grouting pressure during the double grouting process was defined as the fracturing pressure of the double grouting, and it was positively correlated to the interval time between first grouting and secondary grouting. Compared with traditional grouting, double grouting increased the horizontal bearing capacity of the single micropile with the vertical steel floral tube by 24.42%. The horizontal bearing capacity was also 20.25% higher for the structure with three micropiles, compared with a 3-fold value of horizontal sliding resistance. In the test, the maximum bending moment acting on the pile above the sliding surface was located 2.0–2.5 m away from the pile top, and the largest negative bending moment acting on the pile below the slip surface was located 4.0 m away from the pile top. The ultimate bending moment of the single pile increased by 12.8 kN·m with double grouting, and the bending resistance increased by 96.2%. The experimental results showed that the double grouting technology significantly improved the horizontal bearing capacity of the micropile with the steel floral tube, and the soil reinforcement performance between piles was more pronounced. Also, the shear capacity and the flexural capacity were significantly improved compared with the original technology.

Diffusion Tensor Imaging in Patients With Adult Chronic Idiopathic Hydrocephalus

Neurosurgery ◽  
2010 ◽  
Vol 66 (5) ◽  
pp. 917-924 ◽  
Author(s):  
Elke Hattingen ◽  
Alina Jurcoane ◽  
Julia Melber ◽  
Stella Blasel ◽  
Friedhelm E. Zanella ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Normal Pressure ◽  
Clinical Findings ◽  
Control Group ◽  
Microstructural Changes ◽  
Automated Method ◽  
Definition Of ◽  
Lumbar Cerebrospinal Fluid

Abstract OBJECTIVE Diffusion tensor imaging (DTI) parameters were investigated in patients with chronic idiopathic hydrocephalus to evaluate microstructural changes of brain tissue caused by chronic ventricular dilatation. METHODS Eleven patients fulfilling the criteria for possible or probable idiopathic normal pressure hydrocephalus and 10 healthy control subjects underwent MRI at 3 Tesla, including DTI with 12 gradient directions. Patients were scanned before lumbar cerebrospinal fluid (CSF) withdrawal tests. Differences in fractional anisotropy (FA) and mean diffusivity (MD) between patients and controls were assessed using 2 different methods: manual definition of regions of interest and a fully automated method, TBSS (Tract-Based Spatial Statistics). DTI parameters were correlated with clinical findings. RESULTS Compared with the control group, patients with chronic idiopathic hydrocephalus had significantly higher MD values in both the periventricular corticospinal tract (CST) and the corpus callosum (CC), whereas FA values were significantly higher in the CST but lower in the CC. DTI parameters of the CST correlated with the severity of gait disturbances. CONCLUSION Microstructural changes in periventricular functionally relevant white matter structures (CSF, CC) in chronic idiopathic hydrocephalus can be visualized using DTI. Further studies should investigate the change of DTI parameters after CSF shunting and its relation to neurologic outcome.

Hypertension

2012 ◽  
Author(s):  
Gary L. Schwartz
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Disease ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Normal Pressure ◽  
Premature Cardiovascular Disease ◽  
Increased Risk ◽  
Treatment Of Hypertension ◽  
Definition Of ◽  
Over Time

Because blood pressure is a continuously distributed trait in the population and the risk of cardiovascular disease associated with the level of pressure increases progressively as it exceeds 115 mm Hg systolic or 75 mm Hg diastolic, the definition of hypertension is somewhat arbitrary. Currently for adults, it is defined as systolic pressure 140 mm Hg or higher or diastolic pressure 90 mm Hg or higher. Systolic pressures between 120 and 139 mm Hg or diastolic pressures between 80 and 89 mm Hg are classified as prehypertension. Persons who have prehypertension are at increased risk of premature cardiovascular disease and progression to hypertension over time compared with persons who have normal pressure. Epidemiology, diagnosis, and treatment of hypertension are also reviewed.

Acquired Middle Cranial Fossa Fistulas

Neurosurgery ◽  
1979 ◽  
Vol 5 (4) ◽  
pp. 466-472 ◽  
Author(s):  
Benjamin Kaufman ◽  
Howard Yonas ◽  
Robert J. White ◽  
Clinton F. Miller
Keyword(s):  
Cerebrospinal Fluid ◽  
Normal Population ◽  
Normal Pressure ◽  
Middle Cranial Fossa ◽  
Csf Leak ◽  
Middle Fossa ◽  
Middle Fossa Approach ◽  
Cranial Fossa ◽  
Definition Of ◽  
Base Of The Skull

Abstract To the accepted classification of three types of normal pressure, nontraumatic cerebrospinal fluid (CSF) fistulas, we would add “acquired.” This type of CSF fistula tends to occur from the middle cranial fossa because of the enlargement of “pitholes” that are normally present in its anterior medial aspect. The enlargement of these bony defects is due to normal intracranial pressure variations that, not uncommonly, create meningoceles and meningoencephaloceles. A portion of the floor of this area is aerated in up to 10% of the normal population by the lateral recess of the sphenoid sinus, the pterygoid recess. Thus, this area has the potential to act as a pathway between the middle fossa and the paranasal sinuses, allowing cerebrospinal fluid to pass into the sinuses. Isotope and computerized tomographic studies are helpful in the localization of such a CSF leak. Tomography of the base of the skull, however, is essential for the ideal definition of possible routes of fistulization. If there is any question of the presence of a middle fossa fistula, these studies can show whether the floor of this area is pneumatized and whether there are any defects in the floor. The treatment of such a fistula should include generalized reinforcement of the floor of the anterior middle fossa by a middle fossa approach. If any doubt exists as to the site of leakage (anterior or middle fossa), the minimal surgical procedure should include exploration of both areas via a frontotemporal craniotomy.

The Monitoring and Analysis of the Anti-Slide Pile’s Pile-Soil Interaction

2014 ◽  
Vol 633-634 ◽  
pp. 952-957
Author(s):  
Nian Qin Wang ◽  
Yao Qiong Xue ◽  
Xiao Yu Cheng ◽  
Jing Rui Wei
Keyword(s):  
Tensile Stress ◽  
Pressure Distribution ◽  
Compressive Stress ◽  
Slip Surface ◽  
Earth Pressure ◽  
Interaction Force ◽  
Soil Pressure ◽  
High Slope ◽  
Distribution Form ◽  
Pile Cap

In the landslide disaster control and high slope strengthening engineering, anti-slide pile is one of trusted engineering measures, but cognition in aspect of forced state on the anti-slide pile, the pile-soil mechanism etc, which should be strengthened. Therefore, monitoring objects with three cantilever anti-slide pile entities in the loess high slope somewhere, burying monitoring instruments such as earth pressure cells and steel bar meter, for as long as 18 months of monitoring. Through analysis of monitoring results, can draw the following conclusion:①The soil pressure distribution form before the anti-slide piles is parabola-shape as a whole, whatever above the slip surface or under the slip surface the soil pressure distribution form behind the anti-slide piles is almost triangle as a whole;②The anti-slide piles construction are completed, pile-soil interaction force and reinforced by stress reaches stability in about 16 months;③A maximum soil pressure before the anti-slide piles on the ground, the soil pressure behind the anti-slide piles near the potential sliding surface;④Before the anti-slide piles and behind the anti-slide piles, reinforced by stress from pile cap to pile bottom respectively is "compressive stress and tensile stress" and "compressive stress, tensile stress and compressive stress, tensile and compressive stress of zero before pile is tensile stress value maximize after pile.

scholarly journals Evaluation of Overall Stability for Garage Foundation Excavation of High Buildings

2015 ◽  
Vol 9 (1) ◽  
pp. 757-762
Author(s):  
Han Yunshan ◽  
Wu Han ◽  
Dong Yanli ◽  
Wang Yuanlong
Keyword(s):  
Stress Condition ◽  
New Method ◽  
Soil Pressure ◽  
Main Structure ◽  
Load Carrying ◽  
Overall Stability ◽  
Resistance Moment ◽  
The Stability ◽  
Two Sides ◽  
High Building

In current projects, many garages were built after the main structure finished. However, the excavation of garage foundation not only changed the bearing capacity modification by depth, but also makes the soil pressure along the two sides become different. And thus the stress condition of the main building foundations is changed. The change of stress condition affects the stability of main structure directly. Based on the stress condition of high buildings foundation after one side excavation, the change of settlement under the eccentric action was studied. The change of settlement makes the tilt turning appear and thus makes the overturning resistance moment change. The dynamic principle of stability safety factors were also investigated in this paper. The effect of settlement affected by the change of stress condition was considered in the stability analysis of high building. This new method can better and truly evaluate the effect of excavation of foundation on the stability of overturning resistance than the traditional method considering only the static load-carrying capability. The operation of the new method is stronger in the project application for its clear mechanism.

scholarly journals A limit equilibrium analysis of progressive failure in the stability of slopes

1978 ◽  
Vol 15 (1) ◽  
pp. 113-122 ◽  
Author(s):  
K. Tim Law ◽  
Peter Lumb
Keyword(s):  
Slip Surface ◽  
Progressive Failure ◽  
Limit Equilibrium ◽  
Friction Angle ◽  
Soil Mass ◽  
Local Failure ◽  
Equilibrium Analysis ◽  
Stability Of Slopes ◽  
The Stability ◽  
Definition Of

A limit equilibrium method of analysis is proposed for the study of progressive failure in slope stability under a long-term condition. Based on effective stresses, the formulation of the method is derived from consideration of force and moment equilibrium within the soil mass above a prospective slip surface. By dividing the soil mass into a number of vertical slices, recognition of local failure can be made. Once local failure takes place, post-peak strength is assumed to be operative. This then initiates a redistribution of interslice forces and leads to some further local failure. Thus realistic available strengths along the slip surface can be evaluated. This permits the definition of a final safety factor, which is expressed in terms of the actual available reserve of strength. The proposed method has been applied to three well documented case records and encouraging results have been obtained. Based on the assumption that post-peak strengths are given by a friction angle equal to the peak value and a zero cohesion, stability charts have been prepared for design purposes.

scholarly journals Slip surface in narrow backfill behind retaining wall

2021 ◽  
Vol 331 ◽  
pp. 03012
Author(s):  
Abdul Hakam ◽  
Deni Irda Mazni
Keyword(s):  
Factor Of Safety ◽  
Slope Failure ◽  
Slip Surface ◽  
Retaining Wall ◽  
Soil Mass ◽  
Soil Slope ◽  
Soil Pressure ◽  
Earth Reinforcement ◽  
The Stability ◽  
Steep Slopes

For a particular area in Geotechnical engineering, a soil slope is defined as a surface of soil mass which is inclined. It the slope is unstable or has insufficient factor of safety, then it needs to be strengthened by a retaining wall or a particular earth reinforcement to ensue slope failure does not occur. It has long been known that the pattern of slip failure is classified into two main types: translation and rotation. Other patterns of slip failure can be approached within the two mentioned types above. The main purpose of this classification is to assist the engineers in the process of the the stability analysis in purpose to obtain the safety factor of the slope and the reinforcement system if any. For the retaining wall reinforcement analysis, the developed method is generally in the form of soil pressure behind the wall. The pressure due to the self weight of the soil is generated by assuming the backfill is long enough, so that the slip failure can be fully described according to the two main types above. Then in cases where the backfill behind the wall is quite narrow, the method should be corrected or modified. These narrow areas are often found on roads that are built on relatively steep slopes. In this paper, the form of the slip failure behind a narrow retaining wall is presented. The results of this study are very useful for developing analytical methods for retaining soils that are built in narrow areas due to location limitations.

Single Micro Pile in Debris Landslide Anti-Sliding Mechanism Model Test Research

2013 ◽  
Vol 743 ◽  
pp. 237-243
Author(s):  
Qiang Cai ◽  
Ji Ming Kong ◽  
Yin Zhang
Keyword(s):  
Slip Surface ◽  
Test Results ◽  
Soil Pressure ◽  
Soil Arching ◽  
Single Row ◽  
Pile Spacing ◽  
Mechanism Model ◽  
Debris Landslide ◽  
Model Pile ◽  
Sliding Mechanism

Micro-piles are widely used because of its own advantages, but relatively few theoretical studies about its anti-slide mechanism. Firstly, the mechanical properties of the model pile into calibration tests, to get of elastoplastic session elastic modulus, were 0.69×104MPa and 0.04×104MPa.Through the different pile spacing under a single row of miniature pile reinforcement debris landslide indoor model experiment to study the micro-piles against sliding mechanism. The test results show that: different pile spacing, single row of micro-pile soil pressure mainly concentrated in the range of slip surface more than 1/3 of the pile. The smaller pile spacing, soil arching effect, the greater the micro pile skid failure critical moment, the micro pile can withstand landslide thrust the greater skid the better.

Research and Implementation of SOA Application Based on Component Technology

2014 ◽  
Vol 926-930 ◽  
pp. 2378-2381
Author(s):  
Mei Xia Tang
Keyword(s):  
Software Reuse ◽  
Component Technology ◽  
Loose Coupling ◽  
System Implementation ◽  
Application Architecture ◽  
Depth Analysis ◽  
Technical Theory ◽  
Similarities And Differences ◽  
Basic Characteristics ◽  
Definition Of

Taking command of an organization working in the field of research background, first thought SOA architecture provides a brief introduction to analyze the definition of SOA architecture, composition and basic characteristics; then the concept of software reuse and component technology, classification and component specification also gives a brief introduction, and compare the similarities and differences between SOA and component technology. Finally, after the adoption of principles and in-depth analysis of the characteristics and advantages of the above-mentioned technical theory, the actual project - designed on the basis of command system, proposed the use of layered application architecture based on SOA technology components for the overall system implementation. Explore how to design resource layer, component layer, services, processes and access layers to build a good architecture, intended to achieve efficient and loose coupling between the level of purpose, and build applications and develop a multi-command system quickly.

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