Technobius

A review of the current state of 3D subsurface cartography for geotechnical ground characterization

Nurgul Alibekova, Aleksej Aniskin, Kairat Mukhambetkaliev, Indira Makasheva — Sun, 22 Mar 2026 00:00:00 +0500

Three-dimensional subsurface mapping is increasingly used to turn ground investigation evidence into continuous 3D models of soil layers and geotechnical properties that support decisions in ground characterization. This review summarizes the current state of 3D mapping for geotechnical purposes using a citation-guided selection based on Litmaps, resulting in a curated set of 27 studies. The literature is organized into a taxonomy aligned with the Litmaps clustering and grouped into six approach families: implicit or potential-field structural modeling, voxel models and voxel workflows, uncertainty-oriented stochastic and inversion or segmentation approaches, automation and urban-scale pipelines, geophysics-driven 3D modeling, and interoperability and engineering delivery. The comparative analysis shows that practical outcomes depend not only on the final model type but also on workflow design, including data harmonization, modeling rules, and update procedures. Credibility depends on validation methods matched to the target variable and on uncertainty outputs that show where the model is strongly supported by data and where it relies on extrapolation. The review also highlights model comparability as a key operational issue, since mismatches between neighboring models can arise from inconsistent conceptual rules, discretization differences, uneven data density, and asymmetric auxiliary constraints. The paper concludes with an applicability framework, including a decision flow and compact criteria, to guide selection, evaluation, and reporting of decision-grade 3D subsurface mapping products for geotechnical ground characterization.

Microstructural transition and densification behavior of modified soil: a quantitative SEM study

Assel Tulebekova, Natalya Ryvkina, Dauren Yessentay, Akmaral Yeleussinova — Thu, 12 Mar 2026 00:00:00 +0500

This study investigates the microstructural transition and densification behavior of xanthan gum–modified soil using quantitative scanning electron microscopy (SEM) analysis. Soil specimens were prepared with 0%, 3%, 6%, and 9% xanthan gum content. SEM images were processed using image analysis techniques to determine the solid area fraction and characteristic particle size parameters. A densification index was introduced to quantify the ratio between solid and pore phases within the observed microstructure. The results reveal a non-monotonic structural evolution with increasing polymer content. The solid area fraction reached its maximum at 3%, indicating the compact particle arrangement. At 6%, a pronounced decrease in densification was observed, suggesting disruption of particle packing due to non-uniform polymer distribution. At 9%, partial recovery of structural continuity occurred, accompanied by evidence of polymer agglomeration and spatial heterogeneity. Based on quantitative metrics and microstructural observations, three structural stages were identified: discrete particle stage, bridged stage, and matrix-dominated stage. The findings demonstrate that xanthan gum dosage significantly influences soil microstructure in a nonlinear manner. This SEM-based approach provides a systematic framework for identifying microstructural transitions in biopolymer-modified soils.

Refined analytical formulation for static bending and free vibrations of functionally graded beams

Sungat Akhazhanov, Aizhan Nurgoziyeva, Kiyas Kutimov — Sat, 21 Mar 2026 00:00:00 +0500

This paper presents a refined analytical theory for the bending and free vibration analysis of functionally graded (FG) beams accounting for transverse shear deformation. The material properties are assumed to vary continuously through the thickness according to a power-law distribution. Based on the adopted kinematic assumptions, the governing differential equations and effective stiffness relations are derived for both static and dynamic problems. Analytical solutions for the static bending of an FG beam under a uniformly distributed load and for the natural frequencies of free vibrations are obtained. A parametric study is performed to evaluate the influence of the material gradient index ???? and the beam slenderness ratio ????/h. The results show that the dimensionless mid-span deflection increases from 6.2586 to 9.6986 when the gradient index changes from ???? = 1 to ???? = 5 for ????/ℎ = 5. The corresponding dimensionless natural frequency decreases from 3.9710 to 3.4025. Comparisons with the Timoshenko beam theory, Reddy’s higher-order theory, and other refined models demonstrate very good agreement, with differences typically not exceeding 3-5%. The proposed formulation provides a realistic distribution of transverse shear stresses and converges to classical beam solutions for slender beams. The developed model can be effectively applied in the analysis and design of engineering structures made of functionally graded materials.

Effect of waste glass powder particle size, content, and compaction pressure on the properties of autoclaved silicate brick

Sarsenbek Montayev, Bolatbek Sakhiev, Sabit Zharylgapov, Ainur Montayeva — Fri, 27 Mar 2026 00:00:00 +0500

The present study evaluates the influence of waste glass powder particle size distribution, dosage, and compaction pressure on the performance of autoclaved silicate brick. Glass powder produced from container glass waste was incorporated into a quartz–lime mixture at 5, 10, and 15 wt.% in four fractions: ≤63, 63-140, 140-315, and 315-630 μm. The specimens were formed by semi-dry pressing and subjected to autoclave curing. Their average density, compressive strength, water absorption, thermal conductivity, and frost resistance were then determined. The results demonstrated that the modifying effect of glass powder strongly depends on its dispersity. The most favorable performance was obtained with the finest fraction (≤63 μm) at 10 wt.% and 10 MPa compaction pressure, where the average density reached 1860 kg/m³, compressive strength 14.5 MPa, water absorption 11.3%, and thermal conductivity 0.77 W/(m·°C). Coarser fractions showed a progressively weaker effect, and the 315–630 μm fraction was unfavorable relative to the reference composition. Frost resistance remained at F50 for all specimens. Increasing compaction pressure from 5 to 15 MPa enhanced densification and strength development while only slightly changing thermal conductivity. The results confirm the potential of finely ground waste glass as an effective modifying additive for silicate brick production.

Effect of waste glass and silica fume additions on the properties of fired clay ceramics

Fri, 27 Mar 2026 00:00:00 +0500

This study investigates the influence of crushed waste glass (GL) and silica fume (SF) on the densification and microstructural characteristics of fired clay ceramics. Ceramic specimens were prepared by partially replacing clay with 10, 15, and 20 wt.% of GL and SF. They fired at 1050, 1100, and 1125 °C to evaluate the effect of temperature on bulk density and to determine the optimal firing regime. Based on density measurements and visual examination, the samples fired at 1125 °C were identified as the most effective and selected for further evaluation. Water absorption testing and microstructural characterization were conducted for specimens fired at 1125 °C. Increasing firing temperature enhanced densification for all compositions. Glass-modified ceramics exhibited the highest bulk density and lowest water absorption due to intensified liquid-phase sintering and pore filling. In contrast, silica fume additions resulted in comparatively higher porosity and water absorption under identical conditions. Microstructural analysis confirmed a denser and more homogeneous matrix in glass-containing specimens with uniformly distributed Si-, Al-, and Ca-rich phases. The results demonstrate that both additives can modify the properties of fired clay ceramics; however, crushed glass provides a more pronounced improvement in densification and water resistance at 1125 °C.