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The purpose of this paper is to develop an appropriate machine learning model for predicting soil compaction degree while also examining the contribution rates of three influential factors: moisture content, electrical conductivity and temperature, towards the prediction of soil compaction degree.

Taking fine-grained soil A and B as the research object, this paper utilized the laboratory test data, including compaction parameter (moisture content), electrical parameter (electrical conductivity) and temperature, to predict soil degree of compaction based on five types of commonly used machine learning models (19 models in total). According to the prediction results, these models were preliminarily compared and further evaluated.

The Gaussian process regression model has a good effect on the prediction of degree of compaction of the two kinds of soils: the error rates of the prediction of degree of compaction for fine-grained soil A and B are within 6 and 8%, respectively. As per the order, the contribution rates manifest as: moisture content > electrical conductivity >> temperature.

By using moisture content, electrical conductivity, temperature to predict the compaction degree directly, the predicted value of the compaction degree can be obtained with higher accuracy and the detection efficiency of the compaction degree can be improved.

Development of military vehicles capable of surviving shallow-buried explosive blast is seldom done using full-scale prototype testing because of the associated prohibitively high cost, the destructive nature of testing, and the requirements for large-scale experimental-test facilities and a large crew of engineers committed to the task. Instead, tests of small-scale models are generally employed and the model-based results are scaled up to the full-size vehicle. In these scale-up efforts, various dimensional analyses are used whose establishment and validation requires major experimental testing efforts and different-scale models. The paper aims to discuss these issues.

In the present work, a critical assessment is carried out of some of the most important past efforts aimed at developing the basic dimensional analysis formulation for the problem of impulse loading experienced by target structures (e.g. vehicle hull) due to detonation of explosive charges buried to different depths in sand/soil (of different consistency, porosity, and saturation levels).

It was found that the analysis can be substantially simplified if only the physical parameters associated with first-order effects are retained and if some of the sand/soil parameters are replaced with their counterparts which better reflect the role of soil (via the effects of soil compaction in the region surrounding the explosive and via the effects of sand-overburden stretching and acceleration before the associated sand bubble bursts and venting of the gaseous detonation products takes place). Once the dimensional analysis is reformulated, a variety of experimental results pertaining to the total blast impulse under different soil conditions, charge configurations, charge deployment strategies, and vehicle ground clearances are used to establish the underlying functional relations.

The present work clearly established that due to the non-dimensional nature of the quantities formulated, the established relations can be utilized across different length scales, i.e. although they are obtained using mainly the small-scale model results, they can be applied at the full vehicle length scale.

The influence of flood conditions upon traditional cob construction is little understood. This paper aims to investigate the ability of cob materials to resist flood situations and documents basic failure mechanisms. This work also seeks to investigate the wettability characteristics of cob materials utilising environmental scanning electron microscopy.

This paper takes the form of a literature review and case study underpinning laboratory experiments.

Cob walls that are suitably compacted, straw reinforced and are composed and manufactured of the correct materials appear to have the ability to resist total failure when subjected to initial flood conditions, however, the duration to which these structures will remain intact has still to be ascertained, and testing is ongoing. A correlation appears to exist between the rate of cob material's compaction and the duration to which the structural integrity of the walls was retained when the samples were submerged in water. In addition, the use of straw reinforcing increased the duration to which the wall could be submerged before failure. Un‐reinforced cob walls that were submerged in simulated floodwaters, exhibited an undercutting pattern of deterioration prior to failure. The materials for cob construction exhibited both hydrophobic and hydrophilic characteristics. This would have an influence on the material's ability to saturate and dehydrate, and also have an impact on moisture transfer mechanisms. Unsaturated cob wall/samples developed surface tension between hydrophilic surfaces and this is believed by the authors to increase inter‐particle bond strength within the material by the suction effect.

This paper is believed to be the first preliminary investigation into the effect of flooding on cob structures. Additionally, it utilises environmental scanning electron microscopy to reveal information about the surface characteristics of the materials and uses wettability studies to assess the hydrophilic and hydrophobic nature of the aforementioned.

The purpose of this paper is to collect the numerical elaboration of resistances measured on cubes made during the concrete casting and on cores extracted after the completion of the structure, for the concrete used in the construction of the “Esaro” Dam facilities (Cosenza, Italy). In addition to the statistical treatment of the sample, aimed at assessing the analytical congruence with the homogeneous classes provided in the design, the influence of compaction degree on in place strength value was qualitatively evaluated.

The reliability of the concrete during the construction phases was evaluated by two analytical control types according to Italian and European technical rules: “production controls” based on statistical processing of resistance values; “laying controls” that serve to assess the compaction degree with a statistical approach.

Results highlighted in the assessing of compliance checks of the mixture, the fundamental relation between statistical approach and concrete laying control. They become important when is necessary to quantify, especially in the case of great infrastructure, the gap between “potential” and “structural” concrete.

The advantage obtained by controlling the compaction degree in the construction phase is unquestionable. Specifically, it might allow a reduction of the drilling cores, and so minor structural damage, especially for relatively recent structures favouring extensive non-destructive tests.

Describes a set of numerical techniques which implement the rate‐dependent multi‐mechanism deformation (M‐D) constitutive model for rock salt in a finite element code for use in three‐dimensional, finite strain simulations of creep closure in deeply buried salt excavations. Presents essential details of the numerical implementation. The constitutive model is exercised in a three‐dimensional closure simulation of a large underground field experiment. Compares results from the simulation against actual closure measurements taken from the experiment.

To investigate the effect of cement and cement by‐pass dust (CBPD) as a stabilizer on the geotechnical properties of oil‐contaminated soils resulting from leaking underground storage tanks, or soils surrounding petroleum refineries and crude oil wells.

Oil‐contaminated soil (untreated soil) and a soil treated by bio‐remediation (treated soil) as well as a natural soil were obtained from Northern Oman. These soils were stabilized with cement and cement by‐pass dust at 0, 5, 10, 15 and 20 percent, by dry weight of the soil, and cured for seven, 14 and 28 days. Compaction, compressive strength, direct shear, permeability and leaching tests were carried out on the stabilized soils.

The results indicate that cement and cement by‐pass dust improve the properties of oil‐contaminated soils. Traces of arsenic, barium, cadmium, chromium and lead were found in the oil soils, but none of them exceeded the EPA limits.

Reuse in construction applications provides a safe and useful solution for the problem of the disposal of oil‐contaminated soils.

The paper addresses an environmental problem facing many oil companies in disposing of or treating contaminated soil. The approach presented in the paper offers a beneficial, safe and economical solution to this problem.

Despite the dramatic increase in construction toward additive manufacturing, several challenges are faced using natural materials such as Earth and salt compared to the most market-useable materials in 3D printing as concrete which consumes high carbon emission.

Characterization and mechanical tests were conducted on 19 samples for three natural binders in dry and wet tests to mimic the additive manufacturing process in order to reach an efficient extrudable and printable mixture that fits the 3D printer.

Upon testing compressive strength against grain size, compaction, cohesion, shape, heat and water content, X-Salt was shown to record high compressive strength of 9.5 MPa. This is equivalent to old Karshif and fire bricks and surpasses both rammed Earth and new Karshif. Material flow analysis for X-Salt assessing energy usage showed that only 10% recycled waste was produced by the end of the life cycle compared to salt.

Findings are expected to upscale the use of 3D salt printing in on-site and off-site architectural applications.

Findings contribute to attempts to resolve challenges related to vernacular architecture using 3D salt printing with sufficient stability.

Benefits include recyclability and minimum environmental impact. Social aspects related to technology integration remain however for further research.

This paper expands the use of Karshif, a salt-based traditional building material in Egypt's desert by using X-Salt, a salt-base and natural adhesive, and investigating its printability by testing its mechanical properties to reach a cleaner and low-cost sustainable 3D printed mixture.

POROUS metal bearings are produced by partial compaction of metal powders in precision tools of the desired shape followed by the sintering of the powder compact in a reducing atmosphere at a temperature of about 80% of the absolute melting point of the metal. The sintered compact is repressed to restore dimensional accuracy, to produce a high surface finish and, by work hardening, to increase the elasticity. The amount of porosity depends mainly upon the degree of compaction of the powder, and does not change greatly during the subsequent sintering and repressing operations, whereas the size of the pores depends upon the particle size of the powder and the subsequent processing. Finally the porosity is impregnated with lubricating oil.

Explore the development trend of chemically-improved soil in railway engineering.

In this paper, the technical standards home and abroad were analyzed. Laboratory test, field test and monitoring were carried out.

The performance design system of the chemically-improved soil should be established.

On the basis of the performance design, the test methods and standards for various properties of chemically-improved soil should be established to evaluate the improvement effect and control the engineering quality.

Industrial wastes such as copper slag and fly ash are being generated in tons every year and disposed mainly by land fillings, resulting in wastage of useful land. Copper slag in itself is a granular cohesionless sand-like material, while fly ash is highly pozzolanic. The purpose of this paper is to investigate copper slag and fly ash mixes with cement as stabilizer for their proper use in road construction.

Different trial mixes of copper slag and fly ash were tested for obtaining the optimum mix having maximum dry density. Cylindrical specimens were prepared using optimum mix with different proportion of cement (3, 6 and 9 per cent) and cured for period of 7, 14 and 28 days in desiccator. Several tests such as proctor test, unconfined compressive strength test, splitting tensile strength test and soaked CBR test were carried out.

After analyzing the variation of test results with varying cement content and curing period, maximum compressive strength of 10 MPa and maximum tensile strength of 1.5 MPa was found for specimen having 9 per cent cement content cured for a period of 28 days. It was concluded that copper slag and fly ash when mixed in optimum proportion and stabilized with 6 and 9 per cent cement can be effectively used as granular material in sub base and base layer of road pavement.

A typical flexible pavement section was designed and checked using IITPAVE software which gave desired results. This paper may add value in the areas of pavement design, waste utilization, etc.