Pile Cap Designer — MetaMorph Lab

A rigid pile-cap reaction analysis. Pick a standard pile group or draw your own, enter the column loads resolved to the cap, and read each pile's axial and shear reaction — checked live against pile capacity. Reactions use the elastic method: R_z = ΣP/n + ΣM_x·y/I_x + ΣM_y·x/I_y. Compression is negative, tension is positive.

Pile group geometry

Pile diameter in Spacing ft o.c. Min (3×D) ft

Standard configurations — spacing-scaled, PC1…PC21

Column loads at cap

signs by right-hand rule

Col	X	Y	h	P_z	H_x	H_y	M_x	M_y	M_z
	ft	ft	ft	kip	kip	kip	k·ft	k·ft	k·ft

Add pile-cap self weight to compression

Self-weight inputs

Cap thickness in Slab thickness in Soil cover ft Floor live psf Conc. density pcf Soil density pcf

Pile capacity

per geotech report

Allowable compression kips Allowable uplift kips

Estimate allowable compression from soil (ACIP)

Skin friction psf End bearing psf Bearing layer top ft Pile tip depth ft

Governing pile reactions

compression tension (uplift) column load

Group properties

I_x = Σ(y−ȳ)², I_y = Σ(x−x̄)², J = I_x+I_y. Loads are transferred to the group centroid; horizontal loads add moment through the column height h, and ΣM_z distributes as a tangential shear ∝ J.

Per-pile reactions

Pile	X (ft)	Y (ft)	R_z (k)	R_h (k)

Pile cap calcs

Checks compare the governing pile demand against the allowable capacity entered in 03 · Pile capacity. Green = OK, red = No Good. Every term below is the live value being summed into each pile's reaction.