Characteristics Of Earth Pressure Research Articles

Research on the Correction of Soil Pressure Distribution Pattern in Circular Working Wells in Soft Soil Areas

This paper investigates the distribution characteristics of earth pressure on circular caisson foundations in soft soil areas based on practical engineering considerations. Utilizing a three-dimensional numerical analysis model and a displacement-based method for earth pressure calculation, the lateral earth pressure on the retaining structure is examined. Adjustments are made to the distribution pattern of earth pressure on circular caisson foundations in soft soil areas. The study demonstrates that the radius of the caisson significantly influences the spatial distribution of soil pressure. Additionally, empirical formulas for the depth and radius of the reduction in soil pressure around circular caisson foundations are obtained through the research. Comparative analysis reveals that the modified earth pressure planar foundation beam method, which accounts for the arching effect, is simpler, features more mature parameter selection, and is more cost-effective than the three-dimensional finite element method. In comparison to the standard planar elastic foundation beam method for earth pressure, it aligns more closely with the actual direction of displacement.

Active Earth Pressure Characteristics of Light Weight Soil with EPS Particles Behind Rigid Retaining Wall

Active Earth Pressure Characteristics of Light Weight Soil with EPS Particles Behind Rigid Retaining Wall

Bearing Characteristics of Tripod Bucket Foundation under Horizontal and Moment Load in Sand

Based on a series of physical model tests and numerical simulations, the bearing characteristics of a tripod-bucket foundation are investigated. It is found that with the decrease in aspect ratio (L/D), the rotation center of the foundation will decrease, and the displacement model change from rotation to uplift. Characteristics of earth pressure on the buckets from both finite element analysis and model tests are studied, which is used to explain the failure mechanism for tripod-bucket foundations with different L/D. A revised method is proposed to estimate the moment bearing capacity of the tripod bucket foundation under horizontal and moment load. This method is thought to be more convenient and applicable in the practice.

Field test of earth pressure at pile-soil interface by single pile penetration in silty soil and silty clay

Prestressed high-strength concrete (PHC) pipe pile with static press-in method is widely used in recent years. The earth pressure at the pile-soil interface caused by the process of pile jacking has an important influence on the jacked pile construction and even the bearing characteristics. Based on a construction project in Dongying, the change law of earth pressure at pile-soil interface caused by the penetration of PHC pipe pile is analyzed by monitoring the earth pressure at pile-soil interface during pile jacking, and the evolution characteristics of earth pressure at pile-soil interface in viscous soil foundation are revealed. The results show that the earth pressure at the pile-soil interface at different positions (h/B) caused by the penetration of PHC pipe pile gradually increases with time. In the process of pile jacking, the influence of pile jacking on the earth pressure at the pile-soil interface on the pile body and part that exceeds the relative distance of effective pile end (h/B) is weak. In the process of pile jacking, the earth pressure at the pile-soil interface is greatly affected by the relative height of the pile end (h/B), so it is necessary to consider the effect of the pile length to calculate the earth pressure at the pile-soil interface. The phenomenon of "lateral pressure degradation" exists with the increase of h/B in the earth pressure at the pile-soil interface. The research results have certain engineering guiding significance for construction and bearing capacity determination of jacked pile in viscous soil foundation.

Calculation of Reasonable Equivalent Uniform Pressure Height and Lateral Earth Pressure Characteristics of Retaining Structures

Calculation of Reasonable Equivalent Uniform Pressure Height and Lateral Earth Pressure Characteristics of Retaining Structures

Earth pressure on a retaining structure in layered and jointed rock masses

This work looked into the earth pressure induced on retaining walls in different rock layer formations and joint conditions. Based on the simulation of a large-scale expermental test, extended numerical tests were carried out focusing on the effect of various rock layer formations on earth pressure characteristics. The earth pressures induced from single and multi-layered rocks were compared in terms of magnitude and distribution. The comparison showed that a rock layer formation affects the earth pressure on a retaining structure considerably depending on the composition of rock layer with regard to rock type and thickness. Additionally, the analysis results were compared with Peck's soil earth pressure and it was turned out that a layered and jointed rock mass induces the earth pressure considerably different from those both in a single-layer rock mass and in soil ground. The findings form this work can help understand the characteristics of the earth pressure caused by excavation activities in layered and jointed rock masses.

중력식 구조물의 형태에 따른 주동토압 산정과 설계법 제안

In this study theories of earth pressure such as Rankine, Coulomb, Trial Wedge, Improved Trial Wedge, used in the design for onshore and offshore structures, are analyzed and the characteristics of loaded pressure to virtual back (wall, plane) and wall surface in accordance with the structure type are suggested. To investigate characteristics of earth pressure, gravity retaining wall with inclined angle and cantilever wall with inclined ground are movilized for onshore structures and caisson and block type quay wall are mobilized for offshore structures. Based on various theories, the earth pressure applied angle(wall friction angle) and sliding angle toward the wall, which is influenced by the heel length, are calculated and compared. In the case of long heel, the pressure by Rankine`s method in virtual plane and the mobilized angle are most reasonably estimated by the ground slope, and in the case of short heel, the pressure by Coulomb`s method and the mobilized angle by the angle of wall friction. In addition, the sliding angle toward the wall estimated by the improved trial wedge method is large than the value of Rankine`s method. Finally, in this study the reasonable method for calculating the pressure and the mobilized angle that can be applied to the routine design of port structures is proposed. The proposed method can decide the earth pressure with length of a heel and a self weight of retaining wall according to sliding angle toward the wall.

Study on Earth Pressure and Engineering Properties of Solid Waste during Foundation Pit Excavation

A mechanical behavior of solid waste during foundation pit excavation is discussed on the base of the in-situ monitoring results of earth pressure and field measured data in solid waste. During excavation, the soil strength increases, which is mostly because of the variances of characteristics of soil in unloading state. Measurement of earth pressure is less than computation, and the value gradually decreases during excavation. In the end, it tends to be stable or slightly higher than the minimum. Compared with soft soil, the change is not only related to the deformation but also the change of soil property, especially, the influence of fiber to the shear strength of solid waste. By analyzing changing characteristics of earth pressure in solid waste, from the surface of earth within 0m~5m, experience value of lateral earth pressure coefficient is 0.35 during excavation and 0.25 after excavation, and within 5m~10m, the value is 0.55 during excavation and 0.45 after excavation.The conclusions will provide the reference for future similar projects.

Research on Calculation Theory of Double-Row Piles Retaining Structure

The double-row piles retaining structure (DRPRS) is widely applied in the excavation engineering, but its calculation theory is immature and in appropriate. Based on the theory of earth pressure distribution, the distribution characteristics of earth pressure is analyzed to different layout form, and the general formula of earth pressure is derived. From the perspectives of the morphology of slip surface, linear slip surface morphology and broken-line slip surface morphology are proposed based on the feature of the DRPRS. A new calculation model is proposed combining the earth pressure and slip surface morphology. On this basis, one example is used to analyze the force and deformation mechanism of the DRPRS in detail. The research results can guide the engineering practices and promote the development of calculation theory for the DRPRS.

Influence of Culvert Structure Style and Boundary on Vertical Earth Pressure Distribution of High-Filled Culvert

The actual stress state of high filled culvert was not accurately reflected by the calculation method of earth pressure in the prevailing Chinese General Code for Design of Highway Bridges and Culverts. So the vertical earth pressure characteristics of different culvert structural style under fill-load were studied based on field temperature and FEM numerical analysis. Meanwhile, the key influencing factors, such as the height of culvert fill, and boundary condition on the earth pressure characteristics were also discussed. It is shown that the distributions of vertical earth pressure on the middle culvert top and culvert flank wall, as well as culvert side are all nonlinear, they are different from the results calculated by the code method under the high fill load. The influence of the factors on the stress state of high filled culvert should be comprehensively considered. The results can give some references on the design and construction procedure.

실내시험을 통한 이중보온관 되메움 대체재료에 관한 연구

본 논문에서는 자연모래 2종(세사, 왕사)과 부순모래, 자갈 2종(10mm, 20mm)을 대상으로 실내시험을 통하여 입도 분포 특성, 마찰특성 및 토압특성 등 되메움 재료 별 이중보온관의 거동 특성을 평가하고, 합리적인 되메움 대체재료 제시를 위하여 기존 이중보온관 되메움재인 중사와 비교를 수행하였다. 연구결과에 따르면, 부순모래는 5종의 되메움 대체재료 별 평가결과 이중보온관에 미치는 공학적 특성 및 재료의 수급 측면에 있어 기존 중사를 이용하는 이중보온관 되메움재의 대체재료로 가장 합리적인 재료로 평가되었다. This paper recommends the alternative back-fill material for the pre-insulated pipe based on the results of tests performed using different kinds of backfill material. In this study, laboratory tests were preformed to determine the behavior of the pre-insulated pipe caused by variation on grain size distribution, friction characteristics and earth pressure characteristics of different types of backfill material. Two types of natural sand (fine-grained and coarse-grained sand) and crushed sand, and two types of gravel (10mm, 20mm) were used as backfill material in the laboratory tests. The laboratory test results were analyzed and compared with the pre-insulated pipe backfilled with the standard medium-grained sand. Based on the evaluation and comparison of laboratory test results, it was determined that crushed sand is the most suitable back-fill material that can be used as an alternative for medium grained sand for pre-insulated pipes.

A Method for Evaluating the Stability of Cutting Slope Protection Work Subject to Weathered Layer Earth Pressure

In this report, further insight was obtained into earth pressure characteristics of the weathered layer behind slope protection work through laboratory tests based on results from investigations into the actual cutting slopes. Experiments were performed using models built on the measured conditions of weathered layers as determined by the above investigations. The outcome showed that it was possible to reproduce the earth pressure of the weathered layer as obtained from the experiments by considering the friction of the back surface of slope protection work. An evaluation method was then developed on the basis of results from the experiments.

ON THE VISUALIZATION OF PLANAR DISPLACEMENT FIELDS OF A GRANULAR MEDIUM

This report presents results of measurements obtained with the application of photogrammetric false parallax (i.e., the so-called Cameron effect) which has long been recognized as an accurate and expedient method of measuring particle movements in a plane parallel to the photographic image plane. Discussion will be made of the measured displacement fields of a granular medium in relation to earth pressure characteristics which become important in the practice of excavating tunnels at shallow depths, because soil deformations around the tunnel and the ground surface settlements caused by tunnel excavation have not fully been understood at the present stage.