Capacity Of Joints Research Articles

Experimental and numerical investigation of the load-bearing capacity of bolt-fastened wedge active joints for prestressed internal bracing in subway excavations

The present study develops a novel type of active joint node-bolt fasten wedge (BFW) active joints, aiming to investigate the load-bearing capacity of a BFW joint in a quantitative way and put forward precise formulas for its yield load and compression rigidity. To achieve this, indoor axial loading tests were conducted on two BFW joints, accompanied by a set of numerical simulations with the finite element approach implemented in ABAQUS. Parametric research was then conducted to assess the impact of various factors on the yield load and initial compression rigidity of BFW joints, leading to the derivation of precise calculation formulas for accurate prediction of these parameters. The key findings indicate that enhancing the bolt strength from 10.9 to 12.9 significantly improves mechanical performance. Under axial compression, the final bearing force, yield load, and initial compression rigidity increase by 0.86, 1.06, and 0.15 times, respectively. Numerical models accurately predict joint behavior under axial force, confirming their reliability. Parameter studies reveal that increasing web and eaves thickness, bolt strength, and diameter improves bearing capacity, while splint thickness has little effect. The fitting formulas introduced can precisely estimate yield load and rigidity, providing practical value for engineering applications.

Experimental study on bearing capacity performance of glued bamboo-wood bolted joints

The paper presented an experimental investigation of glued bamboo-timber bolted joints to study the influence of bolt grade, bolt diameter, and material type on the load-bearing capacity of bolted joints. The results showed that the failure mode of glued bamboo-timber bolted joints was characterized by compression deformation of the bolt holes, with a plastic hinge failure occurring at each shear plane. Additionally, the failure of the specimens involved the failure of both the primary material and the adjacent substrate at the edge of the joint. As the diameter of the bolts increased, the load-bearing capacity of the specimens also increased. The increase in maximum load from a bolt diameter of 10 mm to 12 mm was 13.78 %, while the increase in maximum load from a bolt diameter of 12 mm to 14 mm was 42.29 %. Enhancing the bolt grade increased the load-bearing capacity of the specimens. The increase could be 10.32 % under the circumstance of WBW (wood on the outer layer and bamboo on the inner layer) combination while 8.4 % when it was BWB (bamboo on the outer layer and wood on the inner layer) combination. Moreover, when the material type was changed into BWB, the increase in load-bearing capacity was 55.33 % and 32.84 % when the diameter varies. The load-bearing capacity of the BWB material was higher than that of the WBW material. After comparing the existing methods of calculating bolt load carrying capacity, optimizations were made to the calculation formulas in Eurocode 5. The modified formula provided more accurate predictions of the load-bearing capacity of glued bamboo-timber bolted joints.

Seismic behavior of exterior joint of CFDST column to steel beam with RC slab

To investigate the seismic performance of an exterior joint connecting concrete-filled double-skin steel tubular (CFDST) column to steel beam with reinforced concrete (RC) slab, four scaled-down joint specimens were designed at a ratio of 1:2. Quasi-static tests were conducted with different axial compression ratios were performed, and the failure mode, hysteresis curve, skeleton curve, bearing capacity, energy dissipation capacity, strength and stiffness degradation, and strain analysis of the composite joint were analyzed. A finite element method (FEM) model of the joint was constructed and validated against the obtained experimental results. Additionally, a parametric study was carried out to investigate the influence of various factors, including the hollow ratio of the CFDST column, the concrete strength of the slab, the thickness of the slab, and the width-to-thickness ratio of the outer steel tube on joint. Based on experimental studies and finite element analysis (FEA), a theoretical calculation method was proposed to evaluate the flexural capacity of the composite joints. The test results showed that the composite exterior joint specimens with RC slab failed at the beam end. Typical failure phenomena of fracture at the steel beam and horizontal end plate interfaces, steel beam flange buckling, and concrete crushing at the RC slab were observed in the experiments. While the interior joint specimen experienced significant plastic deformation and buckling at the column flange. The hysteresis curve of the specimen is elliptical and full without pinching. The presence of RC slab can effectively improve the ultimate bearing capacity, initial stiffness and energy dissipation capacity of the specimen. The FEA results show that the bearing capacity of the composite joints was improved significantly with the increase of the thickness of the slab and the width-thickness ratio of the outer steel tube. The theoretical calculation results of the flexural capacity of the joint are 86 %–112 % of the results of the finite element calculation. The stability and accuracy of the calculation method are excellent and can be effectively applied to calculate the flexural capacity in CFDST composite structural systems.

Seismic performance of earthquake-damaged HSRAC beam-column interior joints rehabilitated by bonding steel plates in the plastic hinge of beams

In order to investigate the seismic performance of earthquake-damaged high-strength recycled aggregate concrete (HSRAC) beam-column interior joints employing ultra-high strength bars (UHSB) in columns, four specimens were designed and manufactured. The research variables included whether the steel tube was encased in the column and whether beams were rehabilitated by bonding steel plates. Among them, the rehabilitated specimens were firstly loaded to 1.0 % drift ratio, and then loaded to failure after rehabilitating the plastic hinge of beams. The test results showed that the beam hinge failure mode occurred in the specimens loaded directly to failure. The damage of columns and joint cores was relatively slight, and the crack width satisfied the repairability limits before 2.0 % drift ratio. The shear failure of the joint core occurred in the rehabilitated specimen without steel tube, as shear deformation and stirrup strain in the joint core increased. The shear bearing capacity of joints increased after steel tubes were encased in columns, and the damage of joint cores was reduced. The bearing capacity and deformation capacity of specimens improved after rehabilitating. Finite element models were established and verified with experiment results. Parameter analysis was conducted for different pre-damage degrees, and the results indicated that as pre-damage degree increased, the bearing capacity of specimens decreased.

Failure mechanism and plastic hinge of RC joints under impact load acting on column ends

Impact loads often act on columns end during accidents such as vehicle impacts and terrorist attacks. The resulting deformations lead to a redistribution of internal forces in the member as well as a reduction in the load carrying capacity. The integrity of the core area of the joint is threatened, which could trigger a progressive collapse. This study numerically investigated the damage and deformation of reinforced concrete (RC) beam-column joints when they are impacted on the column end. The resistance mechanism of joints and the influence of impact location as well as impact velocity was explored. Besides, the deformation capacity of RC beam-column joints under impact loading was quantified using equivalent plastic hinges. It was found that the damage and plastic deformation is concentrated at the impacted column end. The horizontal reaction force at the beam end provides resistance and plays the role as a bearing. The column bottom reaction force is in the same direction as the impact force. However, it is much smaller than the beam end reaction force. The resistance mechanisms within the joints can be categorized into strut-and-tie near the loading point and arches in the mid-span of the beam and column. The core area rotates and has a significant lateral displacement towards the impact location, whether it is loaded at the beam end or the column end. As the impact location moves away from the core aera, the impacted column end exhibit more bending failure. With increasing impact velocity, the impact force, reaction force and total energy absorption of the joint increase. The deformation increases, with more damage occurring in the core area and spreading to the beam. In addition, the plastic curvature was used to describe the actual plastic deformation of the joints, whose maximum occurring at the interface where the impacted column end meets the core area. A formula for the equivalent plastic hinge length of RC joints was proposed, taking into account the effects of impact location and impact velocity.

Mechanical Performances of Concrete-Filled Steel Pipe Composite Segments in Complex Geological Conditions

When shield tunnels are under complex geological conditions, tunnel damage, decreased structural performance, and shield tunnel deformation and destruction may occur. Therefore, a new type of composite segment and combined splicing joint were suggested and experimentally investigated in this study. According to the test results, the new composite segment effectively enhanced the load capacity of the segment, and the yield and ultimate loads of the segment were increased. Compared with the reference specimen, the ultimate load capacities of the proposed segments with different numbers were 23.8%, 50.0%, and 64.3% greater. Moreover, the combined splicing joint enhanced the initial bending stiffness and load capacity of the segment joint, reduced the opening displacement, and improved the rotational stiffness of the segment joint. The addition of a plug-in joint at the segment joint increased its load capacity by approximately 25%. A parametric study showed that the number and posit ion of the plug-in joint clearly affected the load capacity of the segment joint. In addition to the above test results, reasonable theoretical formulas for the new composite segment and combined splicing joint are given in this paper.

Experimental study on shear mechanical properties of concrete joints under different unloading stress paths

In order to study the shear mechanical properties of rock joint under different unloading stress paths, the RDS-200 rock joint shear test system was used to carry out direct shear tests on concrete joint specimens with five different morphologies under the CNL path and different unloading stress paths. The unloading stress paths include unloading normal load and maintaining constant shear load (UNLCSL), unloading normal load and unloading shear load (UNLUSL), unloading normal load and increasing shear load (UNLISL). The results show that the peak shear strength, cohesion, internal friction angle, pre-peak shear stiffness and residual shear strength of concrete joints under CNL path increases with the increasing JRC and normal stress. Under the UNLCSL path, under the same initial shear stress τ1, instability normal stress σi decreases with the increasing JRC, and normal stress unloading amount Δσn increases with the increasing JRC. Under the same JRC, σi increases with the increase of τ1, and Δσn decreases with the increasing τ1. Under the same JRC and σi, τi is significantly smaller under the UNLCSL path than the CNL path. Under the same JRC, the cohesion under the UNLCSL path is less than the CNL path, and the internal friction angle is higher than that the CNL path. Under the same JRC and σi, τi is the largest under the path of CNL and UNLISL, followed by the UNLCSL path, and τi under the UNLUSL path is the smallest. Compared with the CNL path, the variation range of the specimen internal friction angle is within 3% while the average decrease percentage of the specimen cohesion reaches 37.6% under the UNLCSL path, UNLISL, and UNLUSL. Therefore, it can be inferred that the decrease in cohesion caused by normal unloading is the main reason for the decrease in joint instability shear strength. After introducing the correction coefficient k of cohesion to modify the Mohr-Coulomb criterion, the maximum average relative error after correction is only 3.5%, which is significantly improved compared with the maximum average relative error of 56.9% before correction. The research conclusions can provide some reference for the accurate estimation of shear bearing capacity of rock joints under different unloading stress paths, which is of great significance to the stability evaluation and disaster prevention of rock mass engineering.

Ultrasound-guided combined intra-articular corticosteroids injection and suprascapular nerve block for pain control in patients with frozen shoulder

BackgroundFrozen shoulder is an incapacitating disease that causes pain and limitation in the shoulder joint functional capacity. This work aimed to assess the efficacy of ultrasound-guided combined intra-articular corticosteroids (CS) injection and suprascapular nerve block (SSNB) in pain control in patients with frozen shoulders.ResultsOur prospective study included 40 patients, equally divided into two groups: group A; managed with combined ultrasound (US) guided intra-articular corticosteroids injection (IACSI) and SSNB, and group B patients managed with US-guided SSNB. The visual analog scale score statistically significantly improved after both injections. This success was maintained and showed mild improvement at 8-week intervals (with increased patient capability to do physiotherapy after pain control). Similarly, improvement in the functional capacity of the shoulder joint was identified and assessed by the Oxford shoulder score (OSS) in both groups. Mean OSS was statistically significantly higher at 4-week intervals than before the nerve block for groups A and B. At 8 weeks interval, this favorable result was sustained (p < .001).ConclusionsUS-guided SSNB is an effective, radiation-free method to alleviate frozen shoulder-related pains. However, US-guided combined SSNB and IACSI was more effective than SSNB alone in both pain alleviation and improved shoulder joint function.

Experimental Study on the Bending Behavior of Precast Concrete Segmental Bridges with Continuous Rebars at Joints

Longitudinal ordinary rebars are discontinuous at the joints of precast concrete segmental bridges (PCSBs), which can open under tensile stresses induced by bending moments. This will lead to durability issues with the joints. To improve the bending properties of PCSBs, a novel joint type featuring continuous rebars was proposed in the present study. Three specimens were subjected to testing to examine the bending behavior of PCSBs using this new joint design compared to traditional joints. The crack propagation, structural deformation, joint opening width, strain in rebars, failure mode, stiffness, and flexural capacity were comprehensively investigated. The test results reveal that the continuous rebars effectively transferred bending normal stress between joints, ensuring full development of cracks in each beam segment. Effective control of joint opening width was also observed. Compared to traditional joints, the new joints exhibited a 29% to 33% increase in cracking load and a 32% increase in ultimate load. Failure in the continuous rebar joints was characterized by partial anchorage failure of the rebars along with localized concrete crushing in the top compression zone. Based on the test results, a computational method was proposed for calculating the cracking strength and flexural capacity of the new joints.

Development of a new analytical model for circular concrete ring segments with dry joints under combined effects

AbstractPrevious models of circular ring segment joints have been inadequate in describing their loading capacity due to the lack of consideration for the interaction between shear force and bending moment. Consequently, these models have led to over‐ or underestimation of the joints' capacity. The increasing use of dry joint connection technology in wind turbine towers and prefabricated segmental bridge constructions necessitates the development of advanced computational models for these connections. This study presents a new model that considers the effects of bending moment, shear force, and torsion on the loading capacity of circular ring segment joints. Numerical simulations were conducted to validate the developed model under different load combinations, and the results demonstrate excellent agreement between the model predictions and numerical simulations.

Glenohumeral Joint Volume Measurement in Patients with Shoulder Instability: A 3D Volumetric Magnetic Resonance Arthrographic Study.

Background and Objectives: This study aimed to compare capsular volume in patients with shoulder instability to that in control subjects without instability using magnetic resonance (MR) arthrography. The objective was to develop a reliable screening method with which to assess shoulder volume. Materials and Methods: In 21 patients with atraumatic shoulder instability and 21 controls, thin-slice 3D volumetric MR arthrography sequences were obtained. MR arthrography images were uploaded to 3D reconstruction, and 3D images were generated. From the 3D reconstructed images, volumetric measurements of rotator interval (RI), anterior and posterior capsular (AC, PC) recesses, biceps tendon sheath (BS), axillary recess (AR), and total glenohumeral joint (TGJ) were performed. Individuals with any extra-articular contrast leakage were also recorded. Results: A retrospective study analyzed a patient group of 21 individuals with shoulder instability (mean age 29.52 ± 12.83 years) and a control group of 21 individuals without instability (mean age 35.71 ± 12.77 years). No statistically significant differences were identified between the groups with regard to age, gender, or side distribution. The mean total joint volume was significantly higher in the instability group (29.85 ± 6.40 cm3) compared to the control group (23.15 ± 3.48 cm3, p = 0.0001). Additionally, the mean volumes of the RI, AC, PC, BS, and AR were all significantly greater in the patient group compared to the control group. Conclusions: 3D volumetric MR arthrographic measurements of the shoulder joint capacity can provide valuable insights for clinical follow-up and guide surgical treatment decisions in cases of atraumatic shoulder instability.

Multi-scale analysis of ultimate bearing capacity in composite hull joints: failure mechanism and numerical simulation

ABSTRACT Progressive failure analysis method is the main method to analyse the ultimate bearing capacity and failure mode of composite structures. Multi-scale method can effectively reduce the dependence of damage mode and stiffness degradation analysis on material parameters. Based on the multi-scale method, from micro-scale to mesoscale and then to macro-scale, the equivalent modulus and equivalent strength of fibre bundles, single-layer laminates and multi-directional laminates were predicted respectively, and the prediction method of ultimate bearing capacity of large-scale composite structures from material level to structure level was constructed. The mechanical properties of standard composite materials and the ultimate bearing capacity of full-scale composite joints were tested respectively, and the ultimate bearing capacity and failure mode of L-joints were predicted by numerical method. The results show that the numerical simulation method based on multi-scale can accurately predict the ultimate bearing capacity and failure mode of large-scale joints of the hull.

Two-stage coordinated scheduling of hydrogen-integrated multi-energy virtual power plant in joint capacity, energy, and ancillary service markets

With the emergence of distributed resources (DRs), developing an effective, profitable, and green management method is of great importance. Virtual power plant (VPP) can aggregate various DRs, optimize their schedules, and participate in electricity markets uniformly to earn profit. The optimal scheduling problem in spot market has been widely studied, however, few studies have extended the services of VPP to the long-term scale. This paper proposes a coordinated scheduling method for a multi-energy virtual power plant (MEVPP), considering the integration of hydrogen facilities. A holistic market framework, including capacity market, energy market (EM), and ancillary service market (ASM) is developed jointly for the coordination among the annual capacity schedule, daily energy schedule, and daily reserve schedule of MEVPP. A hybrid hydrogen storage system including daily hydrogen storage and seasonal hydrogen storage is modeled to achieve both intraday and cross-seasonal peak shaving. Stochastic programming is used to tackle the uncertainties and risk management is considered by conditional value at risk. With the help of numerical analysis in case studies, it can be concluded that the proposed coordinated scheduling method can improve the economy of MEVPP. The profit from joint market decreases the total cost by about 52 %. The capacity adequacy and flexibility of MEVPP can be improved by the coordination of capacity and reserve services. The hybrid hydrogen storage system can realize the efficient integration of hydrogen and increase hydrogen production and consumption by about 9 %.

Data-driven study on shear bearing capacity of segmental concrete joints

Segmental assembly joints with excellent shear bearing capacity are the key to ensure the integrity of precast concrete girder bridges, which directly affects the force transmission state of the girders. However, with the existence of unfavorable factors such as the multi-key shear capacity reduction effect, the traditional prediction model for calculating the concrete joints shear capacity has poor prediction accuracy and large dispersion. To overcome the shortcomings of the existing prediction model, this study established a database consisting of 311 sets of test data and 110 sets of numerical results based on existing research. A total of seven data-driven models for predicting shear capacity of concrete joints were trained and generated based on the database, namely, two linear models (Linear Regression Support Vector Machine Algorithm, Least Squares Linear Regression) and five nonlinear models (Neural Network Bayesian Regularization; Neural Network Quantized Conjugate Gradient Model, Neural Network Levenberg-Marquardt (LM), Decision Tree, and Gaussian regression). The coefficient of determination (R2), root mean square error (RMSE)，mean absolute error (MAE), error range (A20-index), and error analysis were adopted to evaluate those model's performance. The evaluation results show that the LM model has excellent prediction accuracy, stability, robustness, and can guide the engineering design. Finally, the established database (421 data sets) and trained LM algorithm model were open sourse in this study to promot the investigate of precast concrete structures.

Seismic characteristics of segmental tunnels considering seal roof blocks arrangement

The position of seal roof block may greatly affect the overall performance of the segmental tunnel. However, a few investigations have been dedicated to evaluating this effect. In the present study, finite element models are established to simulate the ring structure-soil model in order to evaluate the capacity curve of the universal ring structure during progressive failure. Nineteen universal ring structures configurations were analyzed considering different locations of the adjacent seal roof blocks. The models accurately simulated the structural details of the typical handhole for curved bolt in the circumferential and longitudinal joints. The seismic performance of the universal ring structure with different configurations is evaluated and discussed in terms of the moment curve, plastic zone distribution, joint opening angle curve and capacity curve of the universal ring. The results indicate that there are significant differences in the maximum positive and negative moment, plastic zone, and tensile angle of the universal ring structure when the seal roof block is in different positions. At the same time, the development of the performance curve of the ring will also show significant differences, especially in the elastic stage. The structure exhibits best seismic performance when the seal roof block is located at arch shoulder and waist (−67.5° ± 22.5°) because it is less likely to reach the normal function, immediate operational, rectifiable or irreparable damage stages compared to other configurations.

An analytical solution for shear bearing capacity of circumferential joints of precast concrete segmental tunnel linings considering dowel action

AbstractThe capacity of the circumferential joint of the precast concrete segmental tunnel lining (PCTL) structure in terms of shear performance principally includes the dowel action by connector/bolt as well as friction force, and it is a vital parameter to assess the mechanical response of the circumferential joint. Further, as there was no analytical model available for precise estimation of a circumferential joint in terms of the shear‐bearing capacity considering the dowel action of the bolt in the presence of axial/normal force, therefore in this investigation, an analytical model has been proposed to estimate the shear‐bearing capacity of the circumferential joint. Furthermore, the analytical model's precision and accuracy were validated via large‐scale experimental investigation on a circumferential joint of PCTL. Upon comparing analytical model outcomes with experimental results, absolute error varied between +5% and −9%, with an average value of the coefficient of friction at the yield point of the bolt. Moreover, the formation of hinges on the side of the bolt within the segment was considered a failure of the circumferential joint. Additionally, the parametric investigation revealed that with just a 1% change in axial force, the diameter, pre‐tightening, and yield strength of the bolt and concrete strength improved by 2.85%, 1%, 0.27%, 0.26% and 0.17% shear‐bearing capacity of the circumferential joint respectively. Axial force variation greatly influences the shear‐bearing capacity of circumferential joint followed by diameter, pre‐tightening, yield strength of the bolt, and concrete strength. Conclusively, with analysis of axial force distribution around the ring for the tunnel, the proposed model has been applied to a full ring to estimate shear bearing capacity.

Comparative study on the bending moment capacity and stiffness of innovative and traditional furniture corner joints

ABSTRACT This study compares the bending moment capacity under compression and bending moment capacity under tension values of eight selected structural furniture joints. Specimens (type L) with a dimension of 150 × 150 × 366 mm were made from three-layer, 18 mm thick particleboard. The corner joints were tested in angular bending in compression and tension. Both classic and new joining elements (plastic cam, zinc cam, one-part plastic connector, screw cam, plastic connector with euroscrew, and birch dowel pre-glued) for the simple assembly of furniture were used in the study. Cam joints with wooden dowels can withstand high stress. There are only minimal differences between joints made of plastic or zinc cams with dowels. If birch dowels with an adhesive coating are added to the plastic joint from sample with plastic connector with euroscrew, this joint will reach 126% higher values in angular bending tests – compressive stress.

КОНСТРУКТОРСКО-ТЕХНОЛОГИЧЕСКОЕ ОБЕСПЕЧЕНИЕ ТРИБОТЕХНИЧЕСКИХ ПАРАМЕТРОВ СОЕДИНЕНИЙ ТРЕНИЯ СКОЛЬЖЕНИЯ В ПРОЦЕССЕ ПРИРАБОТКИ ПРИ СТУПЕНЧАТОМ НАГРУЖЕНИИ

The paper deals with the issues of technological support to provide the load capacity index of cylindrical sliding friction joints during running-in under step stress. The load capacity of sliding friction joints is one of the tribological characteristics, depending on design and technological factors. The results of studying tribotechnical characteristics of cylindrical sliding friction pairs operating under boundary friction conditions are presented. The working surfaces of these triboelements after preliminary finishing (turning with composite 10 or grinding with the periphery of an abrasive wheel) were subjected to various technological methods of antifriction treatment. In particular, the following methods are considered: 1) application of break-in soft films on the surface of triboelements (shafts) by plating methods; 2) application of break-in soft copper-containing films on the surface of the triboelement (shafts) by friction brassing or chemical copper plating; 3) modification of the surfaces of triboelements with solid nitride-containing coatings (combined treatment) in combination with soft break-in films followed by finishing and hardening surface treatment by surface plastic deformation methods. The shafts were made of 45 steel with subsequent hardening, and the inserts were made of bearing materials recommended in the reference literature (antifriction cast iron ASF-1; babbit B -88; bronze BrOCC -5-5-5 ). Logical models of antifriction treatment methods under consideration and the rationale for their application are presented. Experimental studies were carried out by methods of active experiment on a special test bench having a wide range of changes in stresses on the model of the tested compound and relative sliding velocities of triboelements. Statistical treatment of experimental results made it possible to find out the influence of the studied design and technological factors and running-in conditions on the tribotechnical characteristics of the compounds. The research results are analyzed and on their basis practical recommendations for their use are given. Adequate models of forming the load capacity of joints are obtained, which are recommended to be taken into account at the stages of their design (selection of materials and coatings), machining and running-in.

For Malaria Elimination, India Needs to Integrate Its Research and Control Arms.

India has targeted malaria elimination by 2030. The national malaria control program has positioned its strategies in this direction. Substantial support in the form of dynamic research inputs leading to policy formulation and change is needed to steer the country towards malaria elimination. Indian Council of Medical Research (ICMR), India's nodal research body, has been generating evidence and helping to frame several policies ranging from malaria management to vector control operations. Since the country is preparing for malaria elimination, the connection between the programmatic needs and the research agenda needs further strengthening. Typically, the national malaria control program handles the implementation of programmatic activities, while the national research body, ICMR, conducts research studies to generate evidence. We propose a virtual integration of the activities conducted by these two entities to maximize the potential for translating research findings into programmatic policies. Joint monitoring of drug and insecticide resistance, codevelopment and utilization of more innovative surveillance systems, data-backed mitigation responses, and overcoming last-mile challenges are reasons for the virtual amalgamation of the two bodies. Timely translation of research outputs into policy, co-opting of workforce and material resources, joint capacity building, and synergistic advocacy are benefits of the proposed new alliance for more efficient operations. The close functioning will provide impetus to narrow down current gaps and disrupt traditional barriers, galvanizing the country toward malaria elimination.

Experimental investigation of traditional Kath-Kuni wall system and traditional joints

In the Indian Himalayan region, the traditional vernacular construction system is a centuries-old system that is considered a seismic-resistant construction system. This practice is developed in the area over a period of time by the local communities and is never conventionally engineered. Hence, it is important to know about the behaviour of traditional construction systems and key features associated, under gravitational and lateral loading conditions. In the present research, experimental studies have been done on the full scale as well as scaled-down kath-kuni wall specimens, under push-over loading conditions, to characterize its overall behaviour, deformation and earthquake-resisting features. The failure of the kath-kuni wall was governed by friction capacity reduction followed by internal rotation in wooden layers. The kath-kuni system showed high ductile behaviour and the behaviour factor R was calculated as more than 5.4, and was compared with conventional brick masonry. The joints in the kath-kuni wall system have been identified and separate experimental studies, with varying member sizes, have been conducted to find out behaviour and capacity of these traditional joints upon loading. Analytical equations, to calculate capacity, have been proposed and compared with experimental results. The coefficient of friction was found to be varying in between 0.42–0.8 for different surfaces under constant overburden.