Technobius

Geodetic monitoring of building deformations based on total station and GNSS measurements in the city of Kentau

Rustem Akhmetov, Zhanar Bimurat, Aminyam Baltiyeva, Gulmira Makhmetova — Mon, 22 Jun 2026 00:00:00 +0500

Abstract. This study evaluates building deformation in Kentau, Kazakhstan, a post-mining urban area affected by subsidence and flooded underground workings. Two geodetic observation cycles were conducted in May and October 2025 for 14 residential and administrative buildings using GNSS-referenced total station measurements. Reflective markers installed on building corners were observed with a Leica TS10 total station, while local control networks were tied to the city GNSS framework and adjusted in a unified WGS84-based coordinate system. Inter-cycle displacements were then assessed using positional and vertical errors and compared with normative tolerance levels. Valid repeated measurements were obtained for 26 markers on 11 buildings. Approximately 85% of the markers showed planimetric displacement magnitudes below 20 mm, and about 70% showed vertical displacements within ±5 mm. Localized anomalies were recorded at individual markers, including planimetric displacement up to 74.8 mm and vertical displacement values of +616.3 mm and –122.7 mm. The three-marker analysis of building No. 10 indicated differential vertical movement between corners. The results show that GNSS-referenced total station monitoring can provide useful building-scale deformation information in post-mining urban areas, while detected outliers require marker verification, engineering inspection, and continued multi-cycle monitoring.

Mechanical responses of Ili saline loess to EICP treatment under variable salinity and freeze-thaw conditions

Kaixin Shi, Li Ma, Xuejun Liu — Wed, 24 Jun 2026 00:00:00 +0500

This study evaluated the effectiveness of the enzyme-induced carbonate precipitation (EICP) method in improving the mechanical properties of saline Loess from Northwest China under different salinity and freeze-thaw conditions. Four different Na₂SO₄ concentrations (0.16%−3.16%) were used to simulate varying degrees of salinization in the Ili loess, and consolidation tests, unconfined compressive strength tests, and freeze-thaw cycle tests were conducted on both treated and untreated specimens. The results show that in consolidation tests, the effect of EICP treatment on the compressibility of saline loess is significantly modulated by salinity – under low-salinity conditions (≤1.16%), the compression index C_c decreased by up to 19.8%; however, under high-salinity conditions (≥2.16%), C_c actually increased by approximately 17%, indicating a reversal of the cementation effect. Unconfined compressive strength tests and freeze-thaw cycle tests showed that, under low salinity conditions, EICP can effectively enhance particle cementation, increasing strength by 15%−39% and improving freeze-thaw resistance. Under high salinity conditions, however, particularly after undergoing six freeze-thaw cycles, calcium carbonate cementation significantly deteriorated, and the strength of treated specimens was lower than that of untreated specimens. The failure mode gradually evolved from end shear and single shear planes to distributed cracking as the number of freeze-thaw cycles increased, ultimately progressing to complete disintegration. In summary, EICP holds engineering potential for reinforcing loess under low salinity conditions; however, in coupled saline-alkali and cold regions, its applicability requires optimized design based on salinity and freeze-thaw conditions.

Study on the influence of polycarboxylic acid water-reducing agent on the performance of gypsum-modified mud mortar

Sawulet Bekey, Wumeng Liu, Qing Wang, Wenze Wang, Jingzheng Mi — Thu, 25 Jun 2026 00:00:00 +0500

Masonry mortar, as the primary bonding material in adobe construction, plays a crucial role in the integrity of adobe masonry due to its working properties, compressive strength, and shrinkage rate. Based on the use of industrial by-product gypsum for sustainable material modification, gypsum and polycarboxylate superplasticizer were added to address the defects of the masonry mortar and explore their impact. The effect of gypsum on the compressive strength of the mortar specimens exhibited a trend of initially decreasing, then increasing, and eventually decreasing again within a certain range. The experiment found that a 20% gypsum content led to the greatest improvement in compressive strength, reaching 3.12 MPa, which is 1.49 times that of the plain mortar specimens. However, adding gypsum alone negatively affected the mortar's consistency, water retention, and volume shrinkage. Therefore, a combination of polycarboxylate superplasticizer and gypsum was studied to evaluate the mortar's performance. The experiment showed that polycarboxylate superplasticizer effectively improved the consistency and water retention of the gypsum-modified mortar, enabling it to meet the required consistency for masonry under low water-to-soil ratios. The optimal dosage of the superplasticizer ranged from 0.5% to 1.0%, which significantly improved the consistency and water retention properties, with water retention reaching up to 99%. Polycarboxylate superplasticizer also improved the volume shrinkage of the gypsum-modified mortar. With 1% superplasticizer, the volume shrinkage rate of the mortar specimens was reduced to below 10%, almost half of the shrinkage rate of the unmodified mortar. The compressive strength of the gypsum-modified mortar also showed significant improvement with the addition of the superplasticizer. The compressive strength of the mortar increased with the amount of superplasticizer, and when 20% gypsum and 1.5% superplasticizer were mixed, the compressive strength of the mortar specimens reached 5.96 MPa, which is 2.84 times higher than that of the plain mortar specimens.

Flexural behavior of reinforced concrete beams and prediction of failure stages

Abudusaimaiti Kali, Zihao Wang, Alipujiang Jierula — Fri, 26 Jun 2026 00:00:00 +0500

Reinforced concrete (RC) beams are fundamental flexural members in engineering structures. The mechanisms of flexural failure and shear failure differ significantly and directly affect structural safety design. This study systematically investigates the mechanical responses of RC beams with two distinct reinforcement ratios under flexural failure and shear failure. A BP neural network model based on the Bayesian regularization algorithm is developed to predict the failure mode and load state of RC beams. Experimental results of flexural failure indicate that in RC beams, the tensile steel yields first (at a load of 60 kN, the steel strain reaches 1500 µε), followed by concrete crushing and the formation of a plastic hinge. The load‑deflection curve exhibits a pronounced yield flow stage (deflection jumps from 10.10 mm to 15.15 mm), demonstrating ductile failure with early warning characteristics. In contrast, shear failure tests show that under a short shear span ratio, the beam achieves a higher load‑carrying capacity (up to 140 kN, approximately 2.2 times that of the flexural beam) through an arch action. However, the failure is sudden and brittle: as the load increases from 120 kN to 140 kN, the deflection jumps by 4.75 mm, accompanied by a sharp increase in steel strain. Furthermore, the developed BP neural network model takes concrete strain as input and load as output. The regression values for training and testing are all close to 1 (0.994 and 0.996 for the flexural model; 0.999 and 0.998 for the shear model), with small mean square errors. The results demonstrate that the neural network model can predict the load and failure stage of RC beams with high accuracy, providing a reliable basis for engineering design against flexure and shear.

Vibration diagnostics of beam bridges for serviceability assessment: a comparative analysis of international practice

Madina Zarlykova, Denis Tsygulyov, Murat Karacasu — Sun, 21 Jun 2026 00:00:00 +0500

Vibration-based methods are widely used in bridge assessment, yet their engineering interpretation for serviceability evaluation remains inconsistent across studies and national practice. This paper comparatively analyzes international practice in the vibration diagnostics of beam bridges with a focus on how measured dynamic response is translated into conclusions about operational suitability. The analysis covers field-oriented studies and review sources and compares excitation strategies, sensor layouts, measured parameters, interpretation routes, and links between diagnostic results and engineering decisions. Across the reviewed studies, the most frequently used indicators are natural frequencies, mode shapes, damping characteristics, and vibration response levels, since these quantities are sensitive to changes in stiffness, boundary conditions, and structural deterioration. The comparison also shows that these indicators are not equally informative across all field conditions and do not, by themselves, provide a uniform basis for serviceability assessment. Their practical value depends on the test organization, signal interpretation, and the extent to which vibration data are combined with structural models, inspection context, or baseline states. The paper identifies the most transferable findings from international practice and highlights considerations relevant to bridge networks that require practical, selective, and reproducible assessment procedures, including those in Kazakhstan.