Construction of buildings on bored reinforced concrete piles in the area «Gorokhovoye Pole» in Magadan

В работе рассмотрены проблемы возведения фундаментов на территории строительства «Гороховое поле» в г. Магадане, а также описаны инженерно-геологические условия района. Предложена оптимальная технология строительства с использованием бурообсадных железобетонных свай. Описаны преимущества данного типа фундаментов и возможные рекомендации для дальнейшего строительства на территории «Гороховое поле».

Influence of Rainfall Conditions on Stability of Slope Reinforced by Polymer Anti-slide Pile

Traditional reinforced concrete piles have high strength and low cost in slope engineering, but the slow forming and long maintenance period make it difficult to meet the needs of emergency and disaster relief tasks, such as landslides caused by rainfall. In this paper, the influence of a new type of polymer anti-slide pile on slope stability under rainfall conditions is studied. With the advantages of fast forming, high strength, simple construction technology, and small disturbance to slope, the new type of anti-slide pile can meet the requirements of emergency and disaster relief tasks. The influence of different rainfall duration, rainfall form, location, and spacing of pile laying on the stability of rainfall slope is explored with fluid-solid coupling analysis. The results show that the slope stability gradually deteriorates with the increase of the peak duration of rainfall intensity. Without rainfall conditions, the reinforcement effect is optimal when the position of pile cloth is 1/2–3/4 L away from the foot of the slope (L is the horizontal length of the slope); with rainfall conditions, when the position of pile cloth is 1/4–1/2 L away from the foot of the slope, the reinforcement effect is optimal. Without rainfall conditions, the reduction of pile spacing can improve the reinforcement effect; with rainfall conditions, the reduction of pile spacing will affect the flow and discharge of seepage rainwater and reduce the reinforcement effect.

Five-mode quasilinear model of nonlinear dynamics of extended system

Distributed systems are widely used in practice. These are cosmic ligaments in the near-Earth space with a length of tens of kilometers. They approximate reinforced concrete piles in the soil when calculating the stress-strain state and assessing the technical condition; pipelines both in air and in liquid, underwater towed systems. Known underwater airlift systems of great length for the extraction of minerals (nodules) from the ocean floor with a length of 5-10 km. To solve the problems of the dynamics of such systems in various environments, the well-known mathematical models are not quite correct from the point of view of taking into account the variety of wave processes. It determines the need to build refined wave models. A new quasilinear mathematical model, which describes the nonlinear four-mode dynamics of the distributed system in the spatially inhomogeneous field of mass and surface forces, has been obtained. It is described by a nonlinear system of twelve first-order partial differential equations. For it, the principles of ultimate and hyperbolicity are fulfilled. Together with the boundary and initial conditions, it can be used to describe dynamics and statics of geometrically and physically nonlinear rod elements, piles in the ground, crane equipment ropes, mine lifts, aerial cableways, towed systems in liquid and gas flow, etc. For two-mode spatial reduction of the model, the theorem about correctness of Cauchy problem has been considered. As a result of the calculations, the earlier assumptions about the movement of the cable along its initial configuration were changed as the length of the cable changed. It has been found out that this assumption is only true for the initial transition participant. It is also established that at a given tachogram in the configuration of the towed line, there is a point of inflection, which shifts from top to bottom when lifting it. It can be a factor in the looping, contributing to the breakage of the cable system during towing.

Minimizing of tunneling effect on existing infrastructure in Egypt

A set of parametric studies by using the Abaqus software is conducting to investigate the effective method to seal the CWO sewer from the tunneling process. These methods include: (i) two deep grouted walls, (ii) adjacent slurry piles, (iii) bored reinforced concrete piles assisted with slurry piles, and (iv) grouted block confining the twin tunnel wall. Based on the results of parametric studies. Most of the protective studied technique was effective on reducing the tunneling effect on the ground movements.

Selection of the optimal value of compressive stress in concrete under adverse external impacts

This article reviews the effect of static and dynamic compressive stresses on the durability of reinforced concrete structures in aggressive environments. Based on the analysis of previous work and research on this issue, the author describes the main activities to be implemented in the course of works to ensure the durability of concrete and safety of reinforcement. He outlines the necessary measures to reduce the magnitude of dynamic stresses in pile driving and to ensure the healing of microdamage incurred therein. It is proved in the article that the implementation of the proposed set of measures will allow using reinforced concrete piles as supporting structures of quays in harsh climatic conditions.

Deformation of Combined Retaining Structure in Geological Environment

As a new type of sliding support structure, composite support structure has excellent performance. It is a structure in which two rows of reinforced concrete piles are placed in an appropriate position and the front pile head is connected with the back pile body by a rigid beam. It will form a double row spatial structure, similar to the seating. h-type anti-slide pile can save (or even do not need) anchoring components, form a double-row pile supporting structure system, and achieve good supporting performance. By adjusting the position of tie - beam, the new type anti - slide pile has wider universality and applicability. We can make assumptions in the actual calculation.h - type anti - slide pile has strong anti - overturning ability. The compressive strength of the front pile and the tensile strength of the back pile can form a pair of effective anti-overturning bending moments, and the rigid joints also improve the anti-overturning ability.

Study on the effect of some parameters of soil nails on the stability of vertical slopes

Soil nailing is one of the soil reinforcement techniques that has been used worldwide in geotechnical engineering. In Viet Nam, soil nailing technology applied in a number of transportation investments such as Ha Long - Van Don, Bac Giang - Lang Son highways, and some of the hydropower plants in the central provinces of Viet Nam. Soil nailing is a system consisting of reinforced concrete piles and rebars or composite rods installed in an inclined direction into the slope. The research and applications of soil nailing technology to reinforceslopes in Viet Nam have not been widespread. The authors only considered construction technologies, processes, requirements for the materials, equipment, quality - check of soil nails, etc. The optimal geometries of soil nails for the stability of slope are inadequate and analyzed thoroughly. These lead to inaccurate prediction of the construction stabilization effect and the safety of designed structures. In the present study, numerical simulations were conducted to investigate the effects of the inclined angle and the length of soil nail Patterns and subjected to surcharge loads on stability improvement of soil - nailed slopes and facing deformation in a staged - excavation. The research results show that the soil nail reinforcement efficiency could be affected by inclinations and length Pattern s of soil nails. The general conclusion is that the more soil is nailing inclinations, the more the reinforcing forces in the soil nails. The soil nail length Patterns have also influenced displacement characteristics of slopes.