Ductility Of Walls Research Articles

Effect of Vertical Location of Post-Opening on Seismic Behaviour of RC Shear Wall: Experimental and Numerical Analysis

The seismic performance of reinforced concrete (RC) shear walls with post-openings is critical in civil engineering. This study investigates the influence of post-opening positions on the seismic behaviour of RC shear walls through both experimental and numerical approaches. Four shear wall specimens with varying positions of post-openings were subjected to pseudo-static tests. Additionally, Finite Element Method (FEM) simulations were employed to further analyse the structural responses of shear walls with post-openings. The results show that the vertical position of post-openings significantly affects the failure mode, peak bearing capacity, and overall seismic performance. Peak bearing capacity reductions were observed, with central and bottom openings diminishing capacity by up to 17.5% and 15.1%, respectively, while top openings had a minimal impact. Openings also influenced pre-crack initiation, yielding behaviour, and stiffness degradation, with central openings causing the most significant effects. The ductility and energy dissipation capacities of the shear walls were also affected by opening positions. Bottom post-openings led to a maximum ductility reduction of 18.4%, while top openings increased ductility by up to 24.6%. Energy dissipation capacity decreased with lower post-opening locations, with central and bottom openings reducing capacity by 78.9% and 63.0%, respectively. These findings emphasize the importance of considering opening location in the seismic design of RC shear walls to optimize structural performance.

Properties of wood shear walls connected by wood nails

The performance of a wood wall connected by wood nails and twist nails was tested. It was found that during the monotonic load testing, the wood nails connected to the shear panel and stud at the column bottom broke when the deformation reached 12.1 mm. However, the primary failure mode was that the twist nails bent and the head cap became dented in the shear panel. For reciprocating loads, it was found that the wood nails experienced local fracture on the tensile side. The skeleton curve of the wood wall connected by twist nails showed a good trend of bearing capacity changes in both tension and compression sides. Based on the properties of the standard wood wall, a new T-shaped fastener was designed for the midply wood wall. The lateral performance of the reinforced standard wood shear wall and midply wood shear wall were tested. By adding T-shaped pull-up fasteners, sandwich wall structure and double row nails, the strength, stiffness, and ductility of the midply wood wall were substantially better than those of standard walls connected with twist nails using conventional pull-up fasteners.

Tests on seismic and shear performance of RC shear walls under alternating axial tensile and compressive loads

Under strong earthquakes, reinforced concrete (RC) shear walls at the bottom of high-rise buildings may experience an internal force state of alternating tension-shear (-bending) and compression-shear (-bending). In order to clarify the seismic and shear performance of shear walls under alternating axial tensile and compressive loads (referred to as alternating axial loads), cyclic tests on five shear-controlled large-scale RC shear walls were conducted in this study. The tests were conducted with synchronized axial loads and horizontal displacements, and a quantitative analysis of the influence of the alternating axial loads was achieved by setting two control specimens. The crack development, failure modes, load-carrying capacity, deformation capacity, and energy dissipation of the specimens were measured and analyzed. The test results indicate that different axial load cases altered the crack pattern and failure mode. With an increase in the target axial tensile load, both tension- and compression-shear capacities of the specimens under alternating axial loads decreased, with the former experiencing a more significant reduction. In comparison to the tension-shear control specimen, it was observed that the alternating axial loads significantly reduced the displacement ductility of shear walls in the tension-shear state, resulting in substantially lower energy dissipation capacity. In addition, based on the tests in this study and the collected shear wall tests, the shear strength formulas in the current codes ACI 318-19 and JGJ 3–2010, as well as a shear model previously proposed by the authors, were evaluated. Based on the test results, a reduction factor was fitted to account for the effect of alternating axial loads on the compressive-shear capacity of RC walls.

Seismic Performance of Recycled-Aggregate-Concrete-Based Shear Walls with Concealed Bracing

Relatively few studies have been conducted on the seismic performance of recycled aggregate concrete (RAC) shear walls with concealed bracing. To promote the development of high-performance green building structures and the application of RAC in structural components, the seismic performance of RAC shear walls under different influencing factors was tested, and low-cycle reversed loading tests were performed on ten RAC shear walls with different shear-to-span ratios. The test parameters included the recycled coarse aggregate (RCA) replacement ratio, the recycled fine aggregate (RFA) replacement ratio, the axial compression ratio, the shear span ratio and whether to set up the concealed bracing. The influence of the above variables on the seismic performance was then assessed. The results revealed that the bearing capacity, ductility, stiffness and energy dissipation capacity of the RAC shear walls decreased in line with an increase in the replacement ratio of the RFA. However, the bearing capacity, energy consumption and stiffness of the RAC shear walls decreased within 10% and the ductility decreased within 15%. The RAC shear walls were able to meet the seismic requirements of the building structure after reasonable design and use. As the axial compression ratio increased, the bearing capacity of the RAC shear walls improved, but their elastic–plastic deformation capacity was reduced. Setting the concealed bracing significantly improved the seismic performance of the RAC shear walls, such that they achieved a seismic performance close to that of the natural aggregate concrete (NAC) shear wall. After setting up the concealed bracing, the load carrying capacity of the RAC shear walls increased by up to 15%, the ductility increased by up to 20% and the energy consumption capacity increased by up to 50%. A mechanical calculation model of the RAC shear wall was then established by considering the effect of recycled aggregate, the calculated results of which were a good match with the test results.

Finite Element Modeling and Analysis of RC Shear Walls with Cutting-Out Openings

In recent decades, reinforced concrete (RC) shear walls have been one of the best structural solutions to resist lateral load in high-rise buildings. Shear wall openings are essential for preparations and architectural requirements, which weaken the wall, reducing bearing capacity, energy absorption, and stiffness while also causing stress concentrations. This paper presents a comprehensive finite element (FE) investigation of the behavior and performance of RC shear walls with openings and subjected to lateral loads. The study aims to evaluate the influence of various parameters, such as opening location, size, wall aspect ratio, axial load, and concrete strength, which affect the performance of shear walls. FE models were developed to simulate the seismic response of RC shear walls under the combined effect of constant axial and lateral loads. The obtained results from the FE model showed a successful validation using the experimental data available in the literature. The FE analysis results demonstrate that the inclusion of lower openings leads to a 25% decrease in the bearing capacity of the wall when compared to the upper openings. Moreover, it was observed that augmenting the sizes of the openings and the aspect ratios of the wall resulted in declines in the strength, stiffness, and energy absorption capacity of the wall while simultaneously enhancing the ductility and displacement of the RC shear walls.

Seismic performance of carbonated recycled aggregate concrete shear walls

The carbonated modification method is recognized as an effective method to enhance recycled aggregates (RA), but there is currently a lack of research on carbonated recycled aggregate concrete (CRAC) used for structural engineering. This paper investigated the impact of CRAC on the seismic performance of shear walls, quasi-static tests of one natural aggregate concrete (NAC) shear wall and four concrete shear walls with different replacement ratios (30 %, 50 %, 70 %, and 100 %) of carbonated recycled aggregate (CRA) were conducted. The ductility, energy dissipation, stiffness, strength degradation, and lateral displacement components of CRAC shear walls were evaluated. The results indicate that the seismic behavior of the shear walls degraded as the replacement rate of CRA increased. Based on the comprehensive evaluation of failure patterns and seismic performance, the replacement rate of CRA is suggested to be taken as 70 % in the concrete shear walls. Finally, the strut-and-tie model was validated as an effective method for predicting the shear capacity of CRAC shear walls, and the accurate softening coefficient constant C of the strut-and-tie model for CRAC and RAC shear walls was proposed.

Structural Performance of Ferrocement Hollow Shear Walls Subjected to Lateral and Compressive Axial Loads

In this study, ten shear walls were experimentally tested to examine behaviour of ferrocement hollow shear walls subjected to axial and lateral loads. Ferrocement mortar (FM) was used to build eight walls, while normal concrete (NC) was used to build two controls. Walls were lateral reinforced using conventional stirrups, two layers of welded wire mesh (WWM), and expanded steel mesh (ESM). Two specimens lacked lateral reinforcement except for one transverse web in the center of the inner hole. Two symmetric groups of five walls each were created by dividing the walls. While the other group was loaded laterally, one group was loaded axially. In each group, the load–displacement relationship, maximum load and associated displacement, stiffness, ductility, and failure mechanism of FM and NC walls were compared. The results showed that FM walls provided with ESM and WWM had ultimate axial loads that were, respectively, 36% and 19% higher than NC control walls. Ultimate lateral loads and related ultimate drifts of FM walls reinforced with two layers of WWM and ESM were, respectively, 68% and 39%, 96% and 43.5%, larger than control NC wall. For lateral loads greater than those applied to the NC control wall, stiffness increase ratios for FM walls ranged from 2.5% to 89.5%, and for axial loads, they ranged from 20% to 150.5%. The ductility of FM walls increased when compared to NC walls by 58.5% and 158.8% for axial and lateral loading, respectively, when two layers of WWM were utilized to lateral reinforce FM walls. When two layers of ESM were applied to laterally reinforce FM walls in comparison to an NC wall, this increased the walls' ductility under axial and lateral loads by 110.5% and 214.7%, respectively.

Experimental Study on Seismic Performance of Composite Shear Wall with Horizontal Connection and Frame

Prefabricated concrete shear-wall structures are a primary form of prefabricated concrete construction. In this paper, the seismic performance of precast shear walls with frames is studied by experimental methods. The failure characteristics, hysteretic performance, energy dissipation capacity, stiffness degradation, and ductility of the shear wall are mainly analyzed. The results indicate that incorporating various frames into concrete shear walls can significantly enhance the traditional single seismic defense line. The maximum differences between the positive and negative initial stiffnesses of the framed shear wall are 32.6% and 29.7%, respectively. The maximum differences between the positive and negative ductility coefficients compared to the ordinary reinforced concrete shear wall are 15.7% and 20.7%, respectively. The maximum difference in equivalent viscous damping compared to the ordinary reinforced concrete shear wall is 26.5%.

Experimental analysis of RC and SPRC squat shear walls

Squat shear walls employed in nuclear power plants and high-rise buildings often undergo shear failure and exhibit poor ductility. The introduction of built-in steel plate improves the bearing capacity and ductility of shear walls. In this study, experiments were conducted to investigate the bearing and deformation capacity of squat steel plate reinforced concrete composite walls (SPRCW) and traditional reinforced concrete walls (RCW). Key parameters included the axial compression ratio, thickness of steel plates, and loading procedures. Specimens with axial compression ratio of 0.5 demonstrated high bearing capacity and poor ductility with sudden failure. Compared with RCWs, the bearing capacity of SPRCWs with 2 mm and 4 mm thickness steel plate was improved by 13 % and 40 %, respectively, whereas their ductility decreased by 29 % and 4 %, respectively, due to sudden welding failure. The bearing capacity of asymmetric-loaded specimens was slightly smaller than that of symmetric-loaded specimens, however, the ductility of asymmetric-loaded specimens was approximately 15 % greater than that of symmetric-loaded specimens, indicating that the overall damage to concrete significantly impacts ductility. Principal strains calculated from strain gauge rosettes revealed the failure path of SPRCW beginning in the interior of the wall and gradually expanding to the surface. Finally, calculation formulas for the bearing capacity of SPRCW were compared based on the experimental data. The values predicted by JGJ 138 were close to the experimental results, whereas AISC 341 was more conservative.

Experimental studies on the mechanical behaviors of cold-formed thin-walled steel-foam concrete composite walls

This paper presents experimental studies to investigate the compressive and shear behaviors of cold-formed thin-walled steel-foam concrete composite walls. Three compressive walls and three shear walls were tested. The failure mode and load-displacement curve of the specimen were obtained from the compressive experiment. The compressive wall infilled with foam concrete mainly experienced distortion buckling of the end stud and local crushing failure of the concrete. The stud openings had a limited effect on the compressive bearing capacity of the composite wall. The failure mode and load-deformation curve were obtained in shear tests. The ductility index, shear stiffness, yield load, peak load, energy dissipation, and stiffness degradation were analyzed. The shear composite wall filled with foam concrete mainly occurred concrete crushing failure, local or distortional buckling failure of the end stud, and cracking failure of the calcium silicate board. The shear stiffness, shear capacity, ductility, and energy dissipation of the composite wall could be significantly improved after filling with foam concrete.

Experimental study on seismic performance of squat RC shear walls reinforced with hybrid steel and GFRP rebars

This laboratory study investigates the effect of using steel and glass fiber reinforced polymer (GFRP) rebars in shear walls with aspect ratios less than two. The study evaluates six full-scale shear walls subjected to constant axial load and cyclic lateral loading, with aspect ratios of 1.08 and 1.75. The aim is to analyze how the use of steel and GFRP rebars affects crack patterns, fracture, seismic performance, dissipated energy, and ductility of shear walls. The six specimens consist of two reference ones (SRC1 and SRC2) reinforced with steel rebars, two specimens (GRC1 and GRC2) reinforced with GFRP rebars, and two specimens (S-GRC1 and S-GRC2) reinforced with a hybrid of steel and GFRP rebars. The conclusions drawn suggest that employing a hybrid combination of steel and GFRP rebars resulted in a notable alteration of crack propagation behavior and failure mode, transitioning from flexural compression to flexural tension. Additionally, compared to the specimens reinforced solely with GFRP rebars, there was an observed expansion of the hysteresis curve. Additionally, parameters such as cumulative dissipated energy, ductility, and load modification factor based on ductility increased in the S-GRC1 and S-GRC2 specimens compared to the GRC1 and GRC2.

Revealing the microstructure, texture evolution and mechanical properties along the whole wall of Mg-Gd-Y-Zn-Zr cylinders by tailoring rotary backward extrusion parameters

In this article, industrial-specification Mg-Gd-Y-Zn-Zr alloy cylinder parts were successfully prepared by rotary backward extrusion process. The microstructure distribution and mechanical properties evolution of the whole wall of different cylinder parts were investigated, and the effects of different rotation speeds on the microstructure and properties were also revealed. The results showed that the strain of the cylinder wall increased significantly with rotation speed increased, thereby generating a higher driving force for the microstructure refinement. The transformation of the inner wall progressed from the deformed zone (bulk-shaped long period stacking ordered (LPSO) phases, coarse deformed grains, and fine recrystallized grains) to the strongly affected zone (particle-shaped LPSO phases and fine recrystallized grains), with the latter expanding as rotation speed increased. Furthermore, there was a gradient distribution of strain in the cylinder walls, with the strain gradient intensifying alongside rotation speed. The transformation of the strongly affected zone into the deformed region from the inner to the outer wall suggested a diminishing effect of rotation speed on LPSO phases fragmentation and grain refinement. Notably, increasing rotation speed rendered improvements in the strength and ductility of the cylinder wall. And mechanical properties also displayed a gradient decrease from the inner wall to the outer wall. This variation in mechanical properties of different regions was closely associated with the contributions of grain boundary strengthening, texture strengthening and second phase strengthening.

Investigation on laminated steel slit shear walls with low yield steel

To improve the energy dissipation capacity of steel slit shear walls made of thin plates and mitigate the adverse effects from the large out-of-plane deformation and potential local buckling failure, a novel laminated steel slit (LSS) shear wall assembled from two single-layer steel slit (SSS) shear walls is proposed in this study. First, the theoretical analysis method for predicting the shear strength and stiffness of the LSS shear walls is proposed. To validate the theoretical method as well as investigate the hysteretic performance of the LSS shear walls, two specimens made from different materials, common carbon steel and low yield steel, are designed and tested experimentally under quasi-static cyclic loading. Refined finite element models are developed to simulate the hysteretic behaviors of the LSS shear walls, which show good agreement with the test results. Further, the performance differences between the LSS shear walls and SSS shear walls are analyzed using the validated numerical simulation approach. The strength and stiffness of the LSS shear walls are greater than the summation of the individual SSS shear walls, attributed to the interaction between the different layers in the LSS shear walls. The energy dissipation efficiency of the LSS shear walls is improved and the stiffness degradation is effectively delayed, thanks to the incorporation of the low yield steel material. Finally, to evaluate the effects of the contributing factors on the seismic performance of the LSS shear walls, a series of parametric analyses are performed. Parametric analysis results show that the use of the low yield steel helps to improve the ductility and energy dissipation capacity of the LSS shear walls and delay the stiffness degradation. A large link width ratio, small link length ratio and large link thickness ratio can all contribute to a large strength, stiffness and absolute energy dissipation of the LSS shear walls, but the former two at the same time deteriorate the stiffness degradation.

Experimental study and efficient shear-flexure interaction model of reinforced concrete shear walls with UHPC boundary columns

Traditional reinforced concrete (RC) shear walls have insufficient deformation capacity under strong earthquake conditions and are difficult to repair due to severe post-earthquake damage. Ultra-high performance concrete (UHPC) is a cement-based composite material with high strength and toughness, which can be applied to shear walls. Therefore, a new type of RC shear walls with UHPC boundary columns was proposed. A rectangular-shaped shear wall and two shear walls with barbell-shaped sections were tested under axial force and lateral cyclic load, and the effects of UHPC distribution, sectional shape and stirrup strength were studied. The hysteresis characteristics, ductility behavior, energy dissipation and stiffness degradation of all the specimens were analyzed and discussed. The test showed that the shear wall with UHPC boundary columns had good crack-width control ability and the damage degree was greatly alleviated even under large axial forces. The addition of UHPC could enhance the ductility and energy dissipation capacity of shear walls, especially for rectangular-shaped walls. Besides, an efficient shear-flexure interaction (SFI) model was developed for the shear walls and it could accurately capture the lateral load versus lateral displacement relationship and crack orientations. This nonlinear analysis model had fast calculation speed and effective results, with a prediction error of less than 5 % for peak loads.

Research on the axial compressive behavior of double skin composite wall with steel truss

This paper presents a research on the axial compressive behavior of double skin composite wall(DSCW) with steel truss, which is a novel type of composite wall. The steel truss is constructed by two angles and kinked rebar is acting as the interface connector. Experimental study was introduced briefly and software ABAQUS was adopted for numerical simulation analysis. By comparing with the experimental results, the accuracy of the finite element model was verified and then structural behavior of the walls was comprehensively evaluated. A parametric study was carried out to investigate the influences of the strength of steel plate and infilled concrete, truss horizontal spacing to thickness ratio on the compression responses of the composite wall. The results show that the better ductility of the composite wall can be achieved by the lower concrete strength and higher steel plate strength. Besides, the strength of the concrete and the steel plate tends to have a linear correlation with the load-carrying capacity. The horizontal spacing to thickness ratio has the significant influence on the failure mode of the composite wall and local buckling of steel plate can be avoided when the ratio is less than a certain value. In addition, the calculation formula for the axial compressive load-carrying capacity of the composite wall was proposed to provide a reference basis for the application of this type of composite walls in practice.

Comparison and analysis of the seismic performance of windowless and windowed confined masonry walls reinforced with TRC

Unreinforced masonry (URM) walls, especially unreinforced masonry walls with windows, have a low level of seismic protection and are prone to collapse during earthquakes. Reinforcement can improve the seismic performance of walls. In addition, some walls can remain in service after an earthquake with repair reinforcement. To investigate the seismic performance of windowless and windowed masonry walls reinforced with textile-reinforced concrete (TRC) and the effectiveness of TRC in restoring the seismic performance of damaged walls, five walls were designed and tested. The following conclusions were drawn: The TRC facing formed a good constraint on the masonry walls and improved their brittle damage characteristics, but it could not compensate for the weakening effect of window openings. Compared with unreinforced walls, TRC-reinforced walls exhibited better postpeak performance, with higher peak loads, ductility, stiffness, energy dissipation, and other seismic performance indicators. The peak load, stiffness and energy dissipation of the windowed walls were less than those of the windowless walls, but the ductility of the windowed walls was better than that of the windowless walls. For the wall that was predamaged to the peak load and subsequently reinforced, the TRC reinforcement restored the stiffness and ductility to the level of intact walls, but it did not restore the load capacity. The shear capacity calculated by the superposition approach accurately predicts the peak loads of TRC-reinforced walls.

Experimental and numerical study on the load-bearing capacity, ductility and energy absorption of RC shear walls with opening containing zeolite and silica fume

This article originates from an experimental program and nonlinear finite element analysis aimed at examining how pozzolanic concrete influences the behavior of RC shear walls with openings. To achieve this, stress-strain diagrams, and the elastic modulus of 33 cylindrical concrete specimens, each containing varying percentages of silica fume and zeolite (ranging from 0% to 25%), were evaluated. The impact of silica fume and zeolite pozzolans on the ductility and load-bearing capacity of RC shear walls with openings was explored. This was done by analyzing the mechanical properties of the specimens and integrating them into the analytical model. Subsequently, a shear wall with conventional concrete was simulated using the finite element method (FEM). The study delved into the effects of substituting the initial concrete with pozzolanic concrete within the shear wall. Additionally, it investigated the simultaneous reduction in the diameter of the reinforcing bars employed, all in the pursuit of attaining the optimal design for these walls. The findings demonstrated that employing pozzolanic concrete in shear walls, coupled with a balanced configuration of rebar, led to heightened ductility, improved energy absorption, and an enhanced load-bearing capacity for the walls.

Effects of Embedded Expanded Polystyrene Boards on the Hysteretic Behavior of Innovative Precast Braced Concrete Shear Walls

An innovative type of precast braced concrete shear (PBCS) wall has been tested and verified to have comparable shear resistances relative to conventional cast-in-place reinforced concrete (RC) shear walls. The triangular or rectangular embedded expanded polystyrene (EPS) boards in PBCS wall panels can not only considerably reduce concrete use but also reduce the structural weight. To understand the functions of EPS boards in more depth, this paper investigates the effects of the thickness ratio of different shapes of EPS on the hysteretic behaviors of PBCS walls with various shear span ratios (SSRs). The finite element (FE) models of PBCS walls based on the multi-layer shell element are developed and verified to be sufficiently accurate in comparison with the experimental results. The analysis results indicate that the bearing capacity, lateral stiffness and ductility of PBCS walls show a downward trend with the increase in the thickness ratio of EPS boards. The rectangular EPS board has a more pronounced effect on weight reduction as well as concrete use reduction compared to the triangular EPS board under the same thickness ratio. The formulations regarding the bearing capacity are developed and show good agreement with the numerical results. The thickness ratio limit for PBCS walls to satisfy the ductility requirement is addressed. This investigation not only provides insight into the cyclic behavior of PBCS walls with varied thickness ratios but also demonstrates the potential applicability of PBCS walls in precast concrete (PC) structures for both thermal insulation and earthquake resistance purposes.

Experimental and numerical study on seismic behavior of special shaped steel truss and concrete composite shear wall

A steel truss-concrete composite (STCC) shear wall is fabricated by replacing the reinforcement of the shear wall by steel truss, which has high bearing capacity, good fire resistance, good seismic performance, and an easy construction. In order to investigate the seismic performance of special shaped composite shear wall, a quasi-static test was carried out on four T-shaped and two L-shaped composite shear walls. The results showed that the change of diagonal bracing form from strip steel to channel steel can improve the ductility and energy dissipation capacity of the shear wall and delay the strength degradation. Increasing the thickness of steel vertical supports can effectively improve the initial stiffness, while decreasing the thickness of diagonal braces will reduce the bearing capacity of the wall. The strength and stiffness of shear walls loaded along the web in the positive direction (flange in tension) is high, but the ductility is relatively poor when compared with walls loaded in the negative direction (flange in compression). Numerical models were established by ABAQUS, in which the steel hysteretic constitutive model was adjusted to simulate the influence of bond-slip effect. The influence of shear span ratio, axial load ratio, steel ratio of vertical support, volumetric ratio of diagonal brace, tilt angle of diagonal brace and horizontal force direction on the seismic performance of T & L shaped composite shear walls were analyzed. Finally, a design method was proposed, and the calculated results by the design method were in good agreement with the test.

Ascent and emplacement controls of mafic magmas in the mid crust − evidence from 3D modelling of basic bodies of the Koperberg Suite, Namaqualand

Abstract The 3D modelling of basic bodies of the Koperberg Suite (1060 to 1030 Ma) and their wall rocks from Narrap Mine illustrates the distribution, geometries and, by implication, processes that determined the ascent and emplacement of the mantle-derived mafic magmas into the partially-molten, mid-crustal granite-gneiss sequence of the Okiep Copper District in Namaqualand. The lens-like, discontinuous geometry of basic bodies suggests the transfer of the mafic magmas as self-contained, buoyancy-driven hydrofractures. The presence of both shallowly-dipping, foliation-parallel sills and subvertical lenses in zones of steep foliation development, so-called steep structures, indicates an emplacement of the mafic magmas under low deviatoric stresses and irrespective of the regional stress field. Instead, the emplacement of the mafic magmas parallel to pre-existing anisotropies (tectonic fabrics or lithological contacts) highlights those differences in tensile strength and fracture toughness parallel to or across anisotropies determined the propagation of the magmas. This also accounts for the common occurrence of basic bodies in steep structures in which the vertical gneissosity promoted the buoyancy-driven ascent of the mafic magmas. On a regional scale, the mechanical stratification of the subhorizontal, sheet-like granite gneisses and interlayered metasediments exerted important controls on the ascent of Koperberg Suite magmas. The preferential emplacement of basic bodies in schist and gneiss units suggests that the lower rigidity of the ductile wall rocks facilitated magma emplacement through a combination of viscous wall-rock deformation and fracture blunting that led to the arrest of the magma-filled hydrofractures. Multiple intrusive relationships of successively emplaced magma batches suggest that later magmas reutilised earlier established magma pathways, particularly in steep structures. High-rigidity lithologies, such as the massive Springbok Quartzite, in contrast, only allowed for smaller fracture apertures and limited dilation, resulting in the pinching of basic bodies and rather stringer-like geometries. It is conceivable that the higher fracture toughness of the quartzite may also have prevented propagation of the mafic magmas through the Springbok Quartzite and, instead, led to the ponding of basic bodies below the metasediments. The geometry and structural and lithological controls of basic bodies at Narrap Mine are similar to Koperberg Suite intrusions documented from many of the other mine workings in the Okiep Copper District. This suggests similar underlying emplacement controls of the cupriferous rocks, which can be extrapolated on a regional scale and that may guide exploration.